anterior vs prior

anterior and prior both are nouns.

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

As adjectives, anterior and prior are synonyms defined as:

anterior (noun)	prior (noun)
a tooth situated at the front of the mouth	the head of a religious order; in an abbey the prior is next below the abbot

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