greenskeeper vs steward

greenskeeper and steward both are nouns.

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

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

Other hypernyms of greenskeeper include custodian, keeper.

greenskeeper (noun)	steward (noun)
someone responsible for the maintenance of a golf course	someone who manages property or other affairs for someone else
	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