conservator vs steward

conservator and steward both are nouns.

Word	Noun	Adjective	Verb	Adverb
conservator	Yes	No	No	No
steward	Yes	No	No	No

As nouns, steward is a hypernym of conservator; that is, steward is a word with a broader meaning than conservator:

Other hypernyms of conservator include custodian, keeper.

conservator (noun)	steward (noun)
the custodian of a collection (as a museum or library)	someone who manages property or other affairs for someone else
someone appointed by a court to assume responsibility for the interests of a minor or incompetent person	a union member who is elected to represent fellow workers in negotiating with management
	one having charge of buildings or grounds or animals
	an attendant on an airplane
	the ship's officer who is in charge of provisions and dining arrangements