foremother vs ancestor

foremother and ancestor both are nouns.

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

As nouns, ancestor is a hypernym of foremother; that is, ancestor is a word with a broader meaning than foremother:

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

Other hypernyms of foremother include antecedent, ascendant, ascendent, root.

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