Main definitions of seal in English

: seal1seal2



  • 1A device or substance that is used to join two things together so as to prevent them from coming apart or to prevent anything from passing between them.

    ‘blue smoke from the exhaust suggests worn valve seals’
    • ‘Bah, humbug, I say as I scrape the mould off the rubber window seals.’
    • ‘The molded-in membrane creates a much better seal than anything on the market today.’
    • ‘Your dentist will put a rubber seal around your teeth to protect your gums.’
    • ‘The gasket then forms an airtight seal as the jar cools.’
    • ‘The quality of the new seal creates a tighter seal, thus protecting the integrity of the product.’
    • ‘Ice cream packages increasingly are designed with seals, again added for determination of puncture or tears.’
    • ‘For the farm, a changeover to foil seals from plastic lids and a plastic inner seal may save on material waste, but did cause several alterations at the plant.’
    sealant, sealer, adhesive
    View synonyms
    1. 1.1[in singular]The state or fact of being joined or rendered impervious with a seal.
      ‘many fittings have tapered threads for a better seal’
      • ‘While the seal remains intact, the system will report that fact as well, said Steve Farrell, director of product management for hardware at Savi.’
      • ‘The molded-in membrane creates a much better seal than anything on the market today.’
    2. 1.2The water standing in the trap of a drain to prevent sewer gas from backing up through the drain, considered in terms of its depth.
      • ‘Someone finally came up with the concept of a water seal trap.’
      • ‘This P trap has a 1-½ inch water seal to keep sewer gases from entering the building from the drainage system.’
      • ‘Where a trap seal is subject to loss by evaporation, a deep-seal trap consisting of a 4-inch (102 mm) seal or a trap seal primer valve shall be installed.’
  • 2A piece of wax, lead, or other material with an individual design stamped into it, attached to a document to show that it has come from the person who claims to have issued it.

    • ‘The seal was usually impressed on red wax, but was occasionally seen imprinted on a wafer stuck to the instrument with soft wax.’
    • ‘Now the USDA seal confirms for consumers that a product does indeed contain certified organic ingredients.’
    • ‘He replied, handing her a letter with a navy blue wax seal.’
    • ‘I looked at the inky black lettering once more before I broke the wax seal.’
    • ‘Most of the seals were found to consist of mixtures of beeswax and resin.’
    • ‘One purpose of a seal is to authenticate and confirm something as genuine.’
    emblem, symbol, insignia, device, badge, crest, coat of arms, token, mark, monogram, stamp
    View synonyms
    1. 2.1A design resembling a seal embossed in paper as a guarantee of authenticity.
      • ‘Each course was listed, dated, signed by Fred and a raised seal was embossed on the page.’
      • ‘His seal was embossed on the right side of the bottom margin (difficult to see).’
      • ‘The center has tested prototypes for food ecolabels - seals or logos indicating that a product has met a certain set of environmental and/or social standards.’
      • ‘A legitimate card will have a Medicare approved seal.’
      • ‘Today the seal is embossed or printed onto foil disks that are later applied to the document.’
    2. 2.2An engraved device used for stamping a design that authenticates a document.
      • ‘The seals were generally cut from steatite and were carved in intaglio or incised with a copper burin (cutting tool).’
      • ‘Sometimes the seals were not rings but stamps of other kinds, but if it was a ring worn then it was even more creditworthy as only the wearer could make the seal on the document.’
    3. 2.3A decorative adhesive stamp.
      • ‘The US Christmas seal of 1925 features holly and mistletoe behind the candles.’
  • 3A thing regarded as a confirmation or guarantee of something.

    ‘the International Monetary Fund is likely to give a seal of approval to the Mexican plan’
    • ‘Students could subscribe not only to particular areas of knowledge but to particular types of annotations, such as commentary or seals of approval.’
    • ‘Award-winning Highland Park gets royal seal of approval’
    • ‘Do you suppose their products will get seals of approval?’
    • ‘Human rights campaigners worry that it substantially lowers the standard for an international tribunal - while bearing the seal of U.N. approval.’
    • ‘Kitemarks or seals of approval are usually based on checklists of desirable attributes of quality or some other feature of the information.’
    • ‘If such shows risk functioning as institutional seals of approval, they can also serve as testing grounds, occasions to see if the art lives up to the hype.’
    • ‘The scheme certainly has Alex Bright's seal of the approval.’
    • ‘Mudra, he added, means an authentication, a seal that sanctifies or rejects things as Buddhist and non-Buddhist.’
    • ‘It was the seal of heaven's approval on the work of Christ - the clear testimony of the Holy Spirit that the meek and lowly Jesus was the mighty Son of God, who has conquered sin and death for all his people.’
  • 4The obligation on a priest not to divulge anything said during confession.

    ‘I was told under the seal’
    • ‘Is a man bound to hide what he knows under the seal of confession in every case?’
    • ‘A priest cannot break the seal to save his own life, to protect his name, to refute a false accusation, to save the life of another, to aid the course of justice, or to avert a public calamity.’
    • ‘Therefore, there is no reason to think that the Seal of Confession would not have been observed in the Church of England.’


  • 1Fasten or close securely.

    ‘he folded it, sealed the envelope, and walked to the mailbox’
    • ‘Improved packaging also includes using special wrappers, seals, or caps on the outer and/or inner containers, or sealing each dose in its own pouch.’
    • ‘The viral solutions would survive the UV lights only because he would seal the syringes in an opaque biohazard container before leaving.’
    • ‘Brush the edges with water before pressing the lids on top of the fruit mince to seal the filling in.’
    • ‘Dried seeds were sealed in plastic containers and stored at - 20° to prevent them from after-ripening prior to use.’
    • ‘Instead he frowned and stared at the floor, lips tightly sealed.’
    • ‘The problem could be solved by sealing a tiny gap in the church door with a piece of rubber - but strict laws made by British and EU officials to protect bats forbid closing any entrance point.’
    • ‘The van's windows were sealed with vinyl tape and charcoal stoves were found inside.’
    • ‘Krayzelburg refused to provide a sample until he was assured that the containers would be sealed in the presence of German police.’
    • ‘So why didn't the A / C people come prepared to seal the holes in the wall?’
    • ‘Unlike canoes, kayaks are closed on top, rather like a hollowed-out tree trunk, sealing the person in the ‘cockpit‘.’
    • ‘He learned how they took turns writing notes to their loved ones and sealed them in a waterproof container, not knowing if they would be alive to see them delivered.’
    • ‘In portable packaging, its latest developments are the Micro Pak carton and EMP-I packaging machine, which fills and seals this new single-serve carton at speeds up to 8,400 cartons per hour.’
    • ‘For best results, place fumigants in deep runways of the burrow system and seal the openings tightly.’
    fasten, secure, shut, close up, lock, bolt, board up
    stop up, seal up, make airtight, make watertight, close, shut, cork, stopper, stop, plug, block, block up, bung up, clog, clog up, choke, occlude, fill
    View synonyms
    1. 1.1Prevent something from escaping by closing a container or opening.
      • ‘Doubly sealing these items separately keeps food fresher by sealing in moisture better.’
      • ‘After the final wet dressing, apply emollient to the still moist skin to seal the water in the skin before it evaporates.’
      • ‘After you wash your hands, use hand cream to seal in moisture.’
      • ‘Unlike most other swappable phone covers, these shells come complete with keypads, as they are sealed in to the design so as to protect the innards from moisture and dust.’
      • ‘A coating of clear resin seals them in; the surfaces are polished, almost impenetrable.’
      • ‘The strategy is to get water to be absorbed by the outer layer of skin, the stratum corneum and then to seal the water in the skin before it evaporates (which it will do rapidly).’
      • ‘Within three minutes of getting out of the water apply a moisturizer to seal the water in the skin before it can evaporate.’
      • ‘Appret invented a method for preservation by sealing foods in airtight bottles and immersing them in boiling water for varying periods, which led to modern-day canning.’
    2. 1.2Isolate an area by preventing or monitoring entrance to and exit from it.
      ‘the police have sealed off the area in search of the attackers’
      • ‘The area was cleared and the car park was sealed off.’
      • ‘Weapons and ammunition have been also left intact there and the area was not sealed off for safety.’
      • ‘Areas around both shops were sealed off as forensic teams worked to gather clues.’
      • ‘A number of Underground stations could be closed and roads are sealed off.’
      • ‘‘Alleyways are an access point for about 90 per cent of burglaries in the area and by sealing them off we can greatly improve residents' security,’ he said.’
      • ‘However, unless all access points are sealed off, drugs in an intravenous bag could be accessed by even a specialised intrathecal needle and syringe.’
      • ‘Work on this project will not start until the whole area is sealed off and precautions are put in place to prevent an outbreak of the bug aspergillis among patients.’
      • ‘Many businesses have been sealed off for violating the regulations.’
      • ‘Fire officers and crews were quick to arrive at the scene yesterday and the immediate area was sealed off.’
      • ‘The restaurant had to be closed for two hours, as the car park was sealed off and examined for evidence.’
      • ‘He said: ‘The docks and the surrounding area was sealed off.’’
      • ‘The one difference was that here the doors lining the corridor were closed, as though vast areas of the ship had been sealed off.’
      • ‘The scene of the latest shooting was sealed off for detailed forensic examination and Gardaí are carrying out house-to-house enquiries in the hunt for the victim's attackers.’
      • ‘A spokesman said the area close to the A64 had been sealed off purely for evidential purposes, and there was no safety risk.’
      • ‘Most of the fires are under control, and the exposed areas are sealed off.’
      • ‘If it wasn't for the distant cordon of troops sealing the dock area off there wouldn't have been a soldier visible anywhere.’
      • ‘The area has been sealed off for the duration of the search, which is expected to last at least two days.’
      • ‘But when they tried to stop in the car park nearby they found workers were fixing potholes and a third of the spaces and one of the entrances were sealed off.’
      • ‘Just weeks after they had restocked, their farm is sealed off again and their fate - and that of the entire rural community - is being determined by scientists at a Government laboratory.’
      • ‘Last night the 1930s-style bungalow was sealed off as scenes of crime officers investigated the cause of the blaze.’
      close off, shut off, cordon off, fence off, form a ring around, put a cordon sanitaire round, isolate, quarantine, segregate
      View synonyms
  • 2Apply a nonporous coating to (a surface) to make it impervious.

    ‘seal the finish with a satin varnish’
    • ‘Wall and floor tile grout must be sealed to prevent damage from moisture and graffiti.’
    • ‘A perspex cover sealed with silicone grease ensured that the Ringer's solution did not leak from the trough.’
    • ‘Frankly I'd feel much happier with a billion dollars being spent sealing roads in the outback than building tunnels and freeways in the cities which just generate more traffic.’
    • ‘The opening is sutured and sealed with commercial fibrin glue.’
    • ‘The water stress treatments in the present study used containers sealed with parafilm to minimize water loss.’
    • ‘The samples were then prepared on concave microscope slides under coverslips and sealed with silicone grease.’
    • ‘The sample was then placed into a 7-mm Bruker MAS rotor and sealed with parafilm.’
    • ‘Wiping fixtures after each use and keeping sealed with wax will tend to minimize cleaning problems.’
    • ‘Seedlings were fixed in an upright position using plugs of soft polyurethane and sealed with silicone grease.’
    • ‘They have been working to make the gel suitable for sealing cracks in oil wells to prevent water seeping through, and have now been awarded a contract to use it in five sites.’
  • 3Fry (food) briefly in hot fat to prevent it from losing too much of its moisture during subsequent cooking.

    ‘heat the oil and seal the lamb on both sides’
    • ‘Remove from the bag draining the juices off before sealing the meat in a pan with hot oil.’
    • ‘Season the fillet by rubbing it with salt, pepper and olive oil, then seal the fillet in a hot fry pan and add the mushrooms, this will ensure that they soak up the flavours which the beef may leave in the pan.’
    • ‘If you are cooking duck breast, you can remove the skin before sealing the outer flesh in a pan and oven roasting.’
  • 4Conclude, establish, or secure (something) definitively, excluding the possibility of reversal or loss.

    ‘to seal the deal he offered Thornton a place on the board of the nascent company’
    • ‘Substantial losses from overseas investments and a stalled share price effectively sealed his fate.’
    • ‘Chasing a victory target of 80 after dismissing their opponents for 170 earlier today, the tourists sealed their comfortable triumph in just 17.2 overs.’
    • ‘Five minutes later substitute prop Lee Mears was driven over in the corner, which effectively sealed their fate.’
    • ‘Michael gained his qualification after finishing in 55th place in a time of 9: 32: 35, which was enough to seal his place in the championships in October.’
    • ‘Palmer agreed, and the deal was sealed with a simple handshake.’
    • ‘His bronze was Britain's third medal of the Games, sealing a remarkable turnaround in fortune after a dismal first week.’
    • ‘But it appears that Mori's response to the tragedy has effectively sealed his political fate.’
    • ‘He saluted the match winner's wonder strike as York City sealed their first win in seven attempts with a stirring 3-2 victory over Leyton Orient.’
    • ‘In the high-end art world, where six-figure deals are routinely sealed with a handshake, trust is paramount.’
    • ‘Mids sealed their first victory in four matches with more than four overs to spare.’
    • ‘Souths can seal a place in the four with a victory over Brunswick at Thompson Oval in Brunswick Heads.’
    • ‘At 2-0 up after 52 minutes, they should have kicked-on to finish off Borough and virtually seal their place in the premier division next season.’
    • ‘They both converted theirs and the goalkeeper stood firm at the last to seal the place in the finals on March 20 in Durham.’
    • ‘Social contracts are also sealed using buffaloes as guarantees or sureties.’
    • ‘They sealed their second title in two years, with a two games to one victory over Workers Club in the Far North Coast Baseball Grand Final Series.’
    • ‘They sealed their fourth win in six games in the second-half thanks to Parkin's first goal of the season.’
    • ‘The Belgian 10th seed broke twice in the first set which she won in 34 minutes before repeating the performance to seal the match in just over one hour.’
    • ‘The two-try win saw Ospreys seal their fifth victory in six games and end a run of five successes for the Warriors.’
    clinch, secure, settle, conclude, complete, establish
    View synonyms
  • 5Fix a piece of wax or lead stamped with a design to (a document) to authenticate it.

    • ‘And he sealed the document with the seal of arms that his grandfather had worn.’


  • my (or his, etc.) lips are sealed

    • Used to convey that one will not discuss or reveal something.

      • ‘‘Don't worry; I won't tell anyone about your little episode, my lips are sealed.’’
      • ‘Yeah, they do have a history together but my lips are sealed!’
      • ‘Nicholas got the point and made a zipping gesture: ‘Yes, ma'am, my lips are sealed all right.’’
      • ‘But my lips are sealed on what they are, for the moment.’
      • ‘Well, about you thinking that she might have a crush on Joshua, well, my lips are sealed.’
      • ‘You'll have to wait and see because my lips are sealed…’
      • ‘A lady never reveals her age, Sheila, so my lips are sealed!’
      • ‘Indeed, my lips are sealed, but we know that in his heart of hearts that is what Maurice is seeking.’
      • ‘But my lips are sealed… Ooh, I find it hard to keep secrets, but he is really cool.’
      • ‘Tell me all your secrets, because at the moment my lips are sealed.’
  • put (or set) the seal on

    • 1Give the final authorization to.

      ‘the UN envoy hopes to set the seal on a lasting peace’
      • ‘But it's the magical eight-minute closing track which sets the seal on this classic album.’
      • ‘He refused to be disappointed with a solitary point away from home, despite City letting slip a 2-1 lead and missing a number of opportunities to seal the win in the closing stages.’
      • ‘The new contract sets the seal on a fast-growing debut year for the company.’
      • ‘The Trust is due to sign off the deal with its private sector partner, setting the seal on five years of negotiations and planning.’
      • ‘Then at the end of August the chairman announced the sale of the subsidiary - putting the seal on his final retreat from France.’
      • ‘And when Saturday comes around they can deprive the Lions of an historic premiership ‘threepeat’, thus putting the seal on their own unique trifecta.’
      • ‘An excellent individual effort by the new full back put the seal on this victory.’
      • ‘Perhaps this will be the book that finally sets the seal on his reputation and popularity in his native land.’
      • ‘News that it may soon be available to hire for dinners and functions sets the seal on York's growing reputation as a quirky corporate conference destination.’
      • ‘The final pastiche of The Red Balloon, showing that horrible red bag floating over the housetops, sets the seal on this luxury-tourist jaunt.’
      endorse, confirm, guarantee, ratify, validate
      authorize, certify, warrant, authenticate, seal, put the seal on, cap, clinch, wind up, close
      sew up
      View synonyms
      1. 1.1Provide or constitute the final confirmatory or conclusive factor.
        ‘the rain set the seal on his depression’
        • ‘Instead it was Ballyhaunis who found the net to put the seal on a very comfortable victory.’
  • seal someone's fate

    • Make it inevitable that something unpleasant will happen to someone.

      • ‘As she flattens her shoes on the grill, she uses the fingers of both hands to steer the skirt's folded hem forward, sealing its fate forever.’
      • ‘The fact that one of the four buildings in Broad Lane was said to be in need of serious repair, coupled with lack of room to expand the facility, is thought to have sealed their fate.’
      • ‘He seals your fate, but looks confused if you protest.’
      • ‘I had misinterpreted my own future and then taken steps towards this false future, therefore sealing my fate with Mr. Odd.’
      • ‘The little girl spins her head around devilishly to cast the finger in my direction, sealing my fate, casting me out.’
      • ‘And once you resist their military, you're pretty much sealing your fate.’
      • ‘He then takes to visiting the mad ward daily, an act which seals his fate.’
      • ‘But at the end of the day he's courting his own destruction, sealing his fate.’
      • ‘But more mistakes and a first minute penalty sealed their fate.’
      • ‘That inexperience combined with the fact they were playing overseas for the first time sealed their fate.’
  • set (or put) one's seal to (or on)

    • Mark with one's distinctive character.

      ‘it was the Stewart dynasty which most markedly set its seal on the place’
      • ‘A number of nobles, knights and aldermen of Mechelen were called upon to witness and put their seal to the legal document.’
      • ‘The two groups are attempting to set their seal on a key emerging area of wireless technology, mesh networking, by pushing a new standard.’
  • under seal

    • Under legal protection of secrecy.

      ‘the judge ordered that the videotape be kept under seal’
      • ‘Moreover, the agreement was to be executed under seal and such execution requires unconditional delivery and not a delivery in escrow.’
      • ‘It is of some importance to note that the agreement was executed under seal.’
      • ‘So the lawyers want to file materials and their opposing brief under seal.’
      • ‘However, the Powers of Attorney Act 1971 s1 requires that powers of attorney be executed under seal.’
      • ‘I will send two fully numbered copies for you to sign under seal and return to the undersigned.’
      • ‘Although the Trust agreement required that it be signed under seal and witnessed, this is not the case.’
      • ‘They were forced to file their lawsuit under seal (meaning it must be dealt with confidentially) to avoid penalties for violating gag provisions in the Act.’
      • ‘The questioning was therefore conducted under seal in a closed courtroom.’
      • ‘A gratuitous promise, pure and simple, remains unenforceable unless given under seal.’
      • ‘If the mortgage is under seal, he has a statutory right to appoint a receiver or sell the land.’


Middle English ( seal): from Old French seel (noun), seeler (verb), from Latin sigillum small picture diminutive of signum a sign.

Main definitions of seal in English

: seal1seal2



  • 1A fish-eating aquatic mammal with a streamlined body and feet developed as flippers, returning to land to breed or rest.

    • ‘For example, among true seals, the sexually dimorphic species, the northern elephant seal has distinct differences in diving behavior between the sexes.’
    • ‘We camped outside under an enormous Hebridean sky, under the gaze of an inquisitive seal basking in the shallows.’
    • ‘Do you have any experiments being done here with your captive seal population?’
    • ‘However, I subsequently remembered that Canada's annual slaughter of baby fur seals has just got underway again.’
    • ‘At least 155 Hawaiian monk seals have reportedly become entangled in such debris since 1982.’
    • ‘"So when a shark attacks a harbor seal pup, the carcass washes up on shore.’
    • ‘A shore visit to the New Zealand fur seal colony was one of the other highlights of the trip.’
    • ‘The genes of these viruses produce new virus variants, including those with potential to cause epidemics in other animals, like minks, seals, swine, and humans.’
    • ‘A young seal pup appeared from nowhere, performing an underwater ballet for our benefit.’
    • ‘So what lay behind sudden devastation to the island's harbor seal population?’
    • ‘Spinner dolphins, endangered Hawaiian monk seals, and green sea turtles also live here.’
    • ‘The two month hunt will occur at the birthplace of the seals on ice floes off the Atlantic coast.’
    • ‘But that business is encountering its own problems, specifically a bottleneck in processing seal blubber for nutritional supplements.’
    • ‘In the Antarctic, elephant seals are to be recruited.’
    • ‘One Canadian company delivered 50,000 seal carcasses to China during 1994.’
    • ‘Others suggest that marine species were derived at least twice, with one lineage leading to the sea lions and the other to the true seals.’
    • ‘It is among the type A influenza viruses, which can affect humans as well as chickens, ducks, horses, seals, whales, and other animals.’
    • ‘Nunavut communities hunt adult ringed seals, not baby harp seals.’
    • ‘Her comments come on the eve of the biggest seal cull in Newfoundland for decades.’
    • ‘Under the U.S. Endangered Species Act, the Hawaiian monk seal has had some of its coastal habitat protected.’
    • ‘They hunt their primary prey, the ringed seal, from the ice.’
    • ‘Seal Rock actually harvests one of the largest fur seal colonies in the world!’
    • ‘A young seal pup has rejoined his colony after being abandoned by his mother.’
    • ‘An executive spokesman said there were no plans for a seal cull in Scottish waters.’
    1. 1.1
      another term for sealskin


  • Hunt for seals.

    • ‘There were always companies of ducks around when we were out sealing but we would never take a gun in the boat with us.’
    • ‘Every spring for over 100 years, Newfoundland men had gone sealing, aware of the dangers from ice floes and storms.’
    • ‘Today's elders remember how it was to go sealing and evidence from Ozette proves that the hunt is thousands of years old.’


Old English seolh, of Germanic origin.

Main definitions of seal in English

: seal1seal2



  • A member of an elite force within the US Navy specializing in guerrilla warfare and counterinsurgency.

    • ‘Does anyone, for even a second, find him believable as an ex-Navy Seal?’
    • ‘After a military coup in Nigeria, the Seals are sent in to evacuate a small group of foreign nationals, primarily a doctor, from a local mission.’
    • ‘What it does: Seals in moisture, softens and protects.’
    • ‘The Seals operated under their own special type of morality, a morality that can justify almost anything that one does in wartime.’


Abbreviation of (se)a (a)ir (l)and (team).