broad vs adult female

broad and adult female both are nouns.

Word	Noun	Adjective	Verb	Adverb
broad	Yes	Yes	No	No
adult female	Yes	No	No	No

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

Other hypernyms of broad include woman.

broad (noun)	adult female (noun)
slang term for a woman	an adult female person (as opposed to a man)

broad (adjective)	adult female (adjective)
having great (or a certain) extent from one side to the other
showing or characterized by broad-mindedness
lacking subtlety; obvious
broad in scope or content
not detailed or specific
being at a peak or culminating point
very large in expanse or scope
(of speech) heavily and noticeably regional