Definition of injection

• n. - 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.
• n. - That which is injected; especially, a liquid medicine thrown into a cavity of the body by a syringe or pipe; a clyster; an enema.
• n. - The act or process of filling vessels, cavities, or tissues with a fluid or other substance.
• n. - A specimen prepared by injection.
• n. - The act of throwing cold water into a condenser to produce a vacuum.
• n. - The cold water thrown into a condenser.