yes-man vs flunkey

yes-man and flunkey both are nouns.

Word	Noun	Adjective	Verb	Adverb
yes-man	Yes	No	No	No
flunkey	Yes	No	No	No

As nouns, yes-man and flunkey are synonyms defined as:

Other synonyms of yes-man include flunky, stooge.

yes-man (noun)	flunkey (noun)
a person of unquestioning obedience	a person of unquestioning obedience
	a male servant (especially a footman)