mayor vs mayoress

mayor and mayoress both are nouns.

Word	Noun	Adjective	Verb	Adverb
mayor	Yes	No	No	No
mayoress	Yes	No	No	No

As nouns, mayoress is a hyponym of mayor; that is, mayoress is a word with a more specific, narrower meaning than mayor:

Other hyponyms of mayor include ex-mayor, alcalde, burgomaster.

mayor (noun)	mayoress (noun)
the head of a city government	a woman mayor
	the wife of a mayor