beau vs boyfriend

beau and boyfriend both are nouns.

Word	Noun	Adjective	Verb	Adverb
beau	Yes	No	No	No
boyfriend	Yes	No	No	No

As nouns, beau and boyfriend are synonyms defined as:

Other synonyms of beau include fellow, swain.

beau (noun)	boyfriend (noun)
a man who is the lover of a man or woman	a man who is the lover of a man or woman
a man who is much concerned with his dress and appearance