elevator boy vs liftman

elevator boy and liftman both are nouns.

Word	Noun	Adjective	Verb	Adverb
elevator boy	Yes	No	No	No
liftman	Yes	No	No	No

As nouns, elevator boy and liftman are synonyms defined as:

Other synonyms of elevator boy include elevator man.

elevator boy (noun)	liftman (noun)
a man employed to operate an elevator	a man employed to operate an elevator