babu vs adult male

babu and adult male both are nouns.

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

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

Other hypernyms of babu include man.

babu (noun)	adult male (noun)
used as a Hindi courtesy title; equivalent to English `Mr'	an adult person who is male (as opposed to a woman)