antecedent vs sire

antecedent and sire both are nouns.

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

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

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

Other hyponyms of antecedent include ancestress, forbear, forebear, father, forefather, foremother, primogenitor, progenitor.

antecedent (noun)	sire (noun)
the referent of an anaphor; a phrase or clause that is referred to by an anaphoric pronoun	male parent of an animal especially a domestic animal such as a horse
a preceding occurrence or cause or event	the founder of a family
someone from whom you are descended (but usually more remote than a grandparent)	a title of address formerly used for a man of rank and authority
anything that precedes something similar in time

antecedent (adjective)	sire (adjective)
preceding in time or order

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