fiance vs adult male

fiance and adult male both are nouns.

Word	Noun	Adjective	Verb	Adverb
fiance	Yes	No	No	No
adult male	Yes	No	No	No

As nouns, adult male is a hypernym of fiance; that is, adult male is a word with a broader meaning than fiance:

Other hypernyms of fiance include betrothed, man.

fiance (noun)	adult male (noun)
a man who is engaged to be married	an adult person who is male (as opposed to a woman)