[ in-jek-shuh n ]
/ ɪnˈdʒɛk ʃən /


the act of injecting.
something that is injected.
a liquid injected into the body, especially for medicinal purposes, as a hypodermic or an enema.
state of being hyperemic or bloodshot.
Mathematics. a one-to-one function.
Also called insertion. Aerospace. the process of putting a spacecraft into orbit or some other desired trajectory.

Origin of injection

First recorded in 1535–45, injection is from the Latin word injectiōn- (stem of injectiō). See inject, -ion


post·in·jec·tion, adjective re·in·jec·tion, noun su·per·in·jec·tion, noun

Example sentences from the Web for injection

British Dictionary definitions for injection

/ (ɪnˈdʒɛkʃən) /


fluid injected into the body, esp for medicinal purposes
something injected
the act of injecting
  1. the act or process of introducing fluid under pressure, such as fuel into the combustion chamber of an engine
  2. (as modifier)injection moulding
maths a function or mapping for which f(x) = f(y) only if x = y See also surjection, bijection

Derived forms of injection

injective, adjective

Medical definitions for injection

[ ĭn-jĕkshən ]


The act of injecting a substance into a tissue, vessel, canal, or organ.
Something that is injected, especially a dose of liquid medicine injected into the body.
Congestion or hyperemia.

Scientific definitions for injection

[ ĭn-jĕkshən ]

A substance that is introduced into a organism, especially by means of a hypodermic syringe, as a liquid into the veins or muscles of the body.
A function that maps each member of one set (the domain) to exactly one member of another set (the range). Compare bijection surjection.