Definition of injection in English:



  • 1An instance of injecting or being injected.

    ‘painkilling injections’
    ‘an injection of capital was needed’
    • ‘But an amendment was inserted to remove reference to privately-funded city academies and schools that receive extra injections of cash for having a specialism.’
    • ‘It shows that, despite the promise of massive cash injections and a public debate, there is still a massive gulf between people's expectations and the reality of diagnosis.’
    • ‘Filler injections are used to smooth scarred, wrinkled, or furrowed skin on the face.’
    • ‘The injection of local anesthetic serves as a therapeutic trial and may not provide permanent relief.’
    • ‘Your doctor or nurse will give you painkilling tablets or injections to reduce any pain that you have after the operation.’
    • ‘The area is numbed with an injection of local anesthetic.’
    • ‘I think he is one of those managers who got jobs not necessarily because of any real tactical astuteness, but because chairmen felt their club needed a lift or an injection of personality.’
    • ‘There is no proven benefit to topical ointments, suppositories, or injections of local anesthetic.’
    • ‘It also highlighted excessive use of injections and blood transfusions without proper sterilisation.’
    • ‘While the precise details of the scheme are still to be worked out, Labour sources said the preferred option is for the trusts to receive an initial injection of state cash and then build the prisons using private labour and money.’
    • ‘In most instances, they should not receive intramuscular injections.’
    • ‘It has experienced money problems, needing frequent injections of cash to stay alive.’
    • ‘The buy-out will give the business a fresh injection of energy and help us move it forward on its strongest footing.’
    • ‘‘They certainly provide large cash injections for headquarters,’ he says.’
    • ‘Some degree of neck or back pain is common after this operation, but relief can be achieved with pain-killing injections or tablets.’
    • ‘Woodside, wearing a familiar path in Australian corporate history, needed a huge injection of foreign cash to turn its dream into a reality.’
    • ‘The vaccine involves a single injection for children under 12 and two injections for teenagers and adults.’
    • ‘A fully protective course is three intramuscular injections.’
    • ‘No longer concerned with long-term economic development, the authority is banking on a fast injection of international cash merely to stay solvent.’
    • ‘The company had put forward two proposals and the deadline to vote on the second - involving regular cash injections over the next ten years - expired yesterday.’
    administration, introduction
    inoculation, vaccination, vaccine, immunization, booster, dose
    View synonyms
    1. 1.1A thing that is injected.
      ‘a morphine injection’
      • ‘The pain subsided more than usual and I was spared the pin cushion process of endless morphine injections.’
      • ‘In rare instances, insulin injections may cause you to experience breathing or swallowing difficulties.’
      • ‘Participants were randomly given influenza vaccine and placebo injections, at least five days apart.’
      • ‘In the United States erythropoetin injections or autologous blood donations, given preoperatively, are commonly used.’
      • ‘The patient was subjected to mineral oil injections as an experimental therapy to promote hair growth, but no hair growth was ever noted.’
      • ‘A local dermatologist administered cortisone injections with little or no improvement.’
      • ‘In some patients, compensatory sweating can be treated effectively with intradermal botulinum toxin injections.’
      • ‘Cortisone injections usually work within a few days, and the effects can last up to several weeks.’
      • ‘As stated earlier, the duration of results from collagen injections is variable.’
      • ‘Some patients benefit from physical therapy and cortisone injections.’
      • ‘Although I have a very high pain threshold, I was requiring more and more morphine injections.’
      • ‘Other treatments include physical therapy, exercise, cortisone injections and joint replacement surgery.’
      • ‘Intravenous and intradermal opioid injections also may induce itching.’
      inoculation, vaccination, vaccine, immunization, booster, dose
      View synonyms
    2. 1.2[mass noun]The action of injecting.
      ‘the walls have been damp-proofed by injection’
      • ‘Usually they are given by intravenous injection, by infusion pump into a vein or orally.’
      • ‘Biologic treatments may be administered by injection or IV infusion.’
      • ‘Samples were introduced by gravity injection from 20 cm height for 20 s.’
      • ‘Iron sucrose should be administered intravenously, directly into the dialysis line, either by slow injection or by infusion.’
      • ‘Primary mesenchyme cells introduced by injection at the animal pole move in a directed manner to their normal positions in the vegetal region.’
      • ‘EDITOR We have three comments about Pickup et al's meta-analysis comparing insulin infusion with injection, which may cast a different light on their main conclusion.’
      • ‘Half the women received magnesium sulfate by injection or infusion in the hospital over about 24 hours, and the rest got a placebo.’
      administration, introduction
      introduction, instilling, infusion, imbuing, inculcation
      View synonyms
    3. 1.3
      short for fuel injection
      • ‘However, in comparison with more recent rivals, its 3.0 litre diesel engine with a classic injection system and 125 bhp output had begun to seem outclassed.’
      • ‘Prices rise to £20,965 for the seven-seater Sport 2.0-litre turbo diesel injection model.’
      • ‘A proportion of the new model was sold with the carry-over, 2.5 litre, 8 valve, indirect injection diesel engine.’
      • ‘Using revolution counters, the system can analyze the injection parameters of each cylinder and adjust them if necessary.’
      • ‘He would buy new points, plugs and something to put in the injection system.’
      • ‘Compared to the systems in today's direct-injected diesels, the injection systems will probably operate at lower pressures, which will keep the costs down.’
      • ‘Direct injection allows precise control of the quantity of fuel injected and the fuel spray pattern, bringing the petrol engine closer to the efficiency of a diesel.’
      • ‘While the Ford-PSA and Renault engines use the same injection system, the Renault engine has an iron block, two valves per cylinder and is to be made in only one size.’
      • ‘To accomplish the requirements for the multi-material capability that Husky was seeking, a second injection unit was added to the machine.’
      • ‘The common rail also serves as a pressure reservoir while providing furl to the injection jets.’
      • ‘We are making big inroads with our diesel injection technology, and currently we equip the Duramax and Cummins light truck diesel engines with our components.’
      • ‘Also, a dependable brand of fuel injection prevents common injection problems such as varnish deposits, clogging and fuel leakage.’
      • ‘Direct injection yields a stratified charge: a rich mixture near the spark plug with a progressively leaner fuel-air ratio deeper in the cylinder.’
  • 2[mass noun] The entry or placing of a spacecraft or other object into an orbit or trajectory.

    • ‘The spacecraft becomes fully automated after injection into orbit.’
    • ‘The orbit injection by the Ariane rocket used to launch Rosetta was so accurate that only a small amount of fuel was needed to make some tiny corrections.’
    • ‘Since injection into orbit the spacecraft's behaviour has been nominal.’
    • ‘An autonomous telemetry system transmitted data on the payload environment during all the flight phases, from liftoff to in-orbit injection.’
  • 3Mathematics
    A one-to-one mapping.


Late Middle English: from Latin injectio(n-), from the verb inicere (see inject).