proprietress vs adult female

proprietress and adult female both are nouns.

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

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

Other hypernyms of proprietress include owner, proprietor, woman.

proprietress (noun)	adult female (noun)
a woman proprietor	an adult female person (as opposed to a man)