ejector vs ouster

ejector and ouster both are nouns.

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

As nouns, ejector and ouster are synonyms defined as:

ejector (noun)	ouster (noun)
a mechanism in a firearm that ejects the empty shell case after firing	the act of ejecting someone or forcing them out
An injector, ejector, steam ejector, steam injector, eductor-jet pump or thermocompressor is a type of pump.	a wrongful dispossession
a person who ousts or supplants someone else	a person who ousts or supplants someone else