appliance vs injector

appliance and injector both are nouns.

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

As nouns, injector is a hyponym of appliance; that is, injector is a word with a more specific, narrower meaning than appliance:

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

Other hyponyms of appliance include gadgetry, gimbal, mod con.

appliance (noun)	injector (noun)
durable goods for home or office use	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.