The Collaborative International Dictionary of English v.0.48:
Injection \In*jec"tion\, n. [L. injectio : cf. F. injection.]
1. The act of injecting or throwing in; -- applied
particularly to the forcible insertion of a liquid or gas,
by means of a syringe, pump, etc.
2. That which is injected; especially, a liquid inserted
thrown into a cavity of the body by a syringe or pipe; a
clyster; an enema. --Mayne.
(a) The act or process of filling vessels, cavities, or
tissues with a fluid or other substance.
(b) A specimen prepared by injection.
4. (Steam Eng.)
(a) The act of throwing cold water into a condenser to
produce a vacuum.
(b) The cold water thrown into a condenser.
Injection cock, or Injection valve (Steam Eng.), the cock
or valve through which cold water is admitted into a
Injection condenser. See under Condenser.
Injection pipe, the pipe through which cold water is
through into the condenser of a steam engine.
fuel injection, a method of inserting fuel into
internal-combustion engines by directly forcing the liquid
fuel into the combustion chamber at an appropriate point
in the piston cycle; in contrast to carburetion, in
which an air-fuel mixture is drawn in by the downward
stroke of the piston.
[1913 Webster +PJC]