ancestor vs ancestress

ancestor and ancestress both are nouns.

Word	Noun	Adjective	Verb	Adverb
ancestor	Yes	No	No	No
ancestress	Yes	No	No	No

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

ancestor: someone from whom you are descended (but usually more remote than a grandparent)
ancestress: a woman ancestor

Other hyponyms of ancestor include forbear, forebear, father, forefather, sire, foremother, primogenitor, progenitor.

ancestor (noun)	ancestress (noun)
someone from whom you are descended (but usually more remote than a grandparent)	a woman ancestor