injector

Short definition from Wiktionary

Noun

1. 1
   One who, or that which, injects something: One who injects (himself or herself with) psychoactive drugs.
2. 2
   Any of various devices that are used to inject something, as: An apparatus by which a stream of water is forced into a steam boiler.
3. 3
   Any of various devices that are used to inject something, as: Any of the one or more devices in a fuel injection system that create the spray of fuel.
4. 4
   An object that realizes a dependency injection.