Definition of injection in English:



  • 1An instance of injecting or being injected.

    ‘painkilling injections’
    ‘an injection of capital was needed’
    • ‘The buy-out will give the business a fresh injection of energy and help us move it forward on its strongest footing.’
    • ‘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.’
    • ‘A fully protective course is three intramuscular injections.’
    • ‘Filler injections are used to smooth scarred, wrinkled, or furrowed skin on the face.’
    • ‘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.’
    • ‘It also highlighted excessive use of injections and blood transfusions without proper sterilisation.’
    • ‘It has experienced money problems, needing frequent injections of cash to stay alive.’
    • ‘The vaccine involves a single injection for children under 12 and two injections for teenagers and adults.’
    • ‘No longer concerned with long-term economic development, the authority is banking on a fast injection of international cash merely to stay solvent.’
    • ‘‘They certainly provide large cash injections for headquarters,’ he says.’
    • ‘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.’
    • ‘Your doctor or nurse will give you painkilling tablets or injections to reduce any pain that you have after the operation.’
    • ‘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.’
    • ‘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.’
    • ‘There is no proven benefit to topical ointments, suppositories, or injections of local anesthetic.’
    • ‘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.’
    • ‘The area is numbed with an injection of local anesthetic.’
    • ‘The injection of local anesthetic serves as a therapeutic trial and may not provide permanent relief.’
    • ‘In most instances, they should not receive intramuscular injections.’
    inoculation, vaccination, vaccine, immunization, booster, dose
    administration, introduction
    View synonyms
    1. 1.1A thing that is injected.
      ‘a morphine injection’
      • ‘Intravenous and intradermal opioid injections also may induce itching.’
      • ‘Participants were randomly given influenza vaccine and placebo injections, at least five days apart.’
      • ‘The patient was subjected to mineral oil injections as an experimental therapy to promote hair growth, but no hair growth was ever noted.’
      • ‘As stated earlier, the duration of results from collagen injections is variable.’
      • ‘In the United States erythropoetin injections or autologous blood donations, given preoperatively, are commonly used.’
      • ‘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.’
      • ‘Cortisone injections usually work within a few days, and the effects can last up to several weeks.’
      • ‘The pain subsided more than usual and I was spared the pin cushion process of endless morphine injections.’
      • ‘A local dermatologist administered cortisone injections with little or no improvement.’
      • ‘In rare instances, insulin injections may cause you to experience breathing or swallowing difficulties.’
      • ‘Some patients benefit from physical therapy and cortisone injections.’
      • ‘In some patients, compensatory sweating can be treated effectively with intradermal botulinum toxin injections.’
      inoculation, vaccination, vaccine, immunization, booster, dose
      View synonyms
    2. 1.2The action of injecting.
      ‘sometimes a polio vaccine is given by injection’
      • ‘Half the women received magnesium sulfate by injection or infusion in the hospital over about 24 hours, and the rest got a placebo.’
      • ‘Iron sucrose should be administered intravenously, directly into the dialysis line, either by slow injection or by infusion.’
      • ‘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.’
      • ‘Samples were introduced by gravity injection from 20 cm height for 20 s.’
      • ‘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.’
      • ‘Primary mesenchyme cells introduced by injection at the animal pole move in a directed manner to their normal positions in the vegetal region.’
      administration, introduction
      introduction, instilling, infusion, imbuing, inculcation
      View synonyms
    3. 1.3
      short for fuel injection
      • ‘Using revolution counters, the system can analyze the injection parameters of each cylinder and adjust them if necessary.’
      • ‘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.’
      • ‘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.’
      • ‘A proportion of the new model was sold with the carry-over, 2.5 litre, 8 valve, indirect injection diesel engine.’
      • ‘He would buy new points, plugs and something to put in the injection system.’
      • ‘Direct injection yields a stratified charge: a rich mixture near the spark plug with a progressively leaner fuel-air ratio deeper in the cylinder.’
      • ‘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.’
      • ‘To accomplish the requirements for the multi-material capability that Husky was seeking, a second injection unit was added to the machine.’
      • ‘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.’
      • ‘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.’
      • ‘The common rail also serves as a pressure reservoir while providing furl to the injection jets.’
      • ‘Prices rise to £20,965 for the seven-seater Sport 2.0-litre turbo diesel injection model.’
      • ‘Also, a dependable brand of fuel injection prevents common injection problems such as varnish deposits, clogging and fuel leakage.’
  • 2The 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.’
    • ‘An autonomous telemetry system transmitted data on the payload environment during all the flight phases, from liftoff to in-orbit injection.’
    • ‘Since injection into orbit the spacecraft's behaviour has been nominal.’


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