businesswoman vs adult female

businesswoman and adult female both are nouns.

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

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

Other hypernyms of businesswoman include bourgeois, businessperson, woman.

businesswoman (noun)	adult female (noun)
a female businessperson	an adult female person (as opposed to a man)