sire vs ancestor

sire and ancestor both are nouns.

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

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

sire: the founder of a family
ancestor: someone from whom you are descended (but usually more remote than a grandparent)

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

sire (noun)	ancestor (noun)
male parent of an animal especially a domestic animal such as a horse	someone from whom you are descended (but usually more remote than a grandparent)
the founder of a family
a title of address formerly used for a man of rank and authority

sire (verb)	ancestor (verb)
make (offspring) by reproduction