ejector vs doer

ejector and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
ejector	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of ejector; that is, doer is a word with a broader meaning than ejector:

Other hypernyms of ejector include actor, worker.

ejector (noun)	doer (noun)
a mechanism in a firearm that ejects the empty shell case after firing	a person who acts and gets things done
An injector, ejector, steam ejector, steam injector, eductor-jet pump or thermocompressor is a type of pump.
a person who ousts or supplants someone else