poetess vs adult female

poetess and adult female both are nouns.

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

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

Other hypernyms of poetess include poet, woman.

poetess (noun)	adult female (noun)
a woman poet	an adult female person (as opposed to a man)