Source : Webster's Revised Unabridged Dictionary (1913)
Injector \In*ject"or\, n.
1. One who, or that which, injects.
2. (Mach.) A contrivance for forcing feed water into a steam
boiler by the direct action of the steam upon the water.
The water is driven into the boiler by the impulse of a
jet of the steam which becomes condensed as soon as it
strikes the stream of cold water it impels; -- also called
{Giffard's injector}, from the inventor.
Source : WordNet®
injector
n : a contrivance for injecting (e.g., water into the boiler of
a steam engine or particles into an accelerator etc.)