meaning of injection
1. The act of injecting or throwing in; -- applied particularly to the forcible throwing in of a liquid, or aeriform body, by means of a syringe, pump, etc.
2. That which is injected; especially, a liquid medicine thrown into a cavity of the body by a syringe or pipe; a clyster; an enema.
3. The act or process of filling vessels, cavities, or tissues with a fluid or other substance.
4. A specimen prepared by injection.
5. The act of throwing cold water into a condenser to produce a vacuum.
6. The cold water thrown into a condenser.
7. the forceful insertion of a substance under pressure