antecedent vs anterior

antecedent and anterior both are nouns.

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

antecedent (noun)	anterior (noun)
the referent of an anaphor; a phrase or clause that is referred to by an anaphoric pronoun	a tooth situated at the front of the mouth
a preceding occurrence or cause or event
someone from whom you are descended (but usually more remote than a grandparent)
anything that precedes something similar in time

antecedent (adjective)	anterior (adjective)
preceding in time or order	of or near the head end or toward the front plane of a body
	earlier in time