injector vs contraption

injector and contraption both are nouns.

Word	Noun	Adjective	Verb	Adverb
injector	Yes	No	No	No
contraption	Yes	No	No	No

As nouns, contraption is a hypernym of injector; that is, contraption is a word with a broader meaning than injector:

injector: a contrivance for injecting (e.g., water into the boiler of a steam engine or particles into an accelerator etc.)
contraption: a device or control that is very useful for a particular job

Other hypernyms of injector include appliance, contrivance, convenience, gadget, gismo, gizmo, widget.

injector (noun)	contraption (noun)
a contrivance for injecting (e.g., water into the boiler of a steam engine or particles into an accelerator etc.)	a device or control that is very useful for a particular job
An injector, ejector, steam ejector, steam injector, eductor-jet pump or thermocompressor is a type of pump.