poetess vs poet

poetess and poet both are nouns.

Word	Noun	Adjective	Verb	Adverb
poetess	Yes	No	No	No
poet	Yes	No	No	No

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

poetess: a woman poet
poet: a writer of poems (the term is usually reserved for writers of good poetry)

Other hypernyms of poetess include adult female, woman.

poetess (noun)	poet (noun)
a woman poet	a writer of poems (the term is usually reserved for writers of good poetry)