Definition from Wiktionary, the free dictionary
See also înjection
injection (plural injections)
- The act of injecting, or something that is injected.
- (specifically, medicine) Something injected subcutaneously, intravenously, or intramuscularly by use of a syringe and a needle.
- (set theory) A function that maps distinct x in the domain to distinct y in the codomain; formally, a f: X → Y such that f(a) = f(b) implies a = b for any a, b in the domain.
- (mathematics) A relation on sets (X,Y) that associates each element of Y with at most one element of X.
- (figuratively) The addition of money to someone, or to a business.
- The troubled business received a much-needed cash injection.
- (programming, code) The insertion of program code into an application, URL, hardware, etc.
- a SQL injection exploit allowing a malicious user to modify a database query
- A specimen prepared by injection.
- (steam engines) The act of throwing cold water into a condenser to produce a vacuum.
- (steam engines) The cold water thrown into a condenser to produce a vacuum.
Derived terms 
(programming, code) Insertion of program code into an application, URL, etc.
Related terms 
act of injecting, or something injected
medicine: something injected
set theory: one-to-one mapping
See also 
injection f (plural injections)