anteroom vs vestibule

anteroom and vestibule both are nouns.

Word	Noun	Adjective	Verb	Adverb
anteroom	Yes	No	No	No
vestibule	Yes	No	No	No

As nouns, anteroom and vestibule are synonyms defined as:

Other synonyms of anteroom include antechamber, entrance hall, foyer, hall, lobby.

anteroom (noun)	vestibule (noun)
a large entrance or reception room or area	a large entrance or reception room or area
	any of various bodily cavities leading to another cavity (as of the ear or vagina)