American Dictionary of the English Language

INJECT'ION, noun [Latin injectio.] The act of throwing in, particularly that of throwing a liquid medicine into the body by a syringe or pipe.

1. A liquid medicine thrown into the body by a syringe or pipe; a clyster.

2. In anatomy, the act of filling the vessels of an animal body with some colored substance, in order to render visible their figures and ramifications.