/in jek"sheuhn/ , n.
1. the act of injecting.
2. something that is injected.
3. a liquid injected into the body, esp. for medicinal purposes, as a hypodermic or an enema.
4. state of being hyperemic or bloodshot.
5. Math. a one-to-one function.
6. Also called insertion . Aerospace. the process of putting a spacecraft into orbit or some other desired trajectory.
[ 1535-45; injection- (s. of injectio ). See INJECT, -ION ]