anteroom vs entrance hall

anteroom and entrance hall both are nouns.

Word	Noun	Adjective	Verb	Adverb
anteroom	Yes	No	No	No
entrance hall	Yes	No	No	No

As nouns, anteroom and entrance hall are synonyms defined as:

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

anteroom (noun)	entrance hall (noun)
a large entrance or reception room or area	a large entrance or reception room or area