anterior vs frontal

anterior and frontal both are nouns.

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

anterior (noun)	frontal (noun)
a tooth situated at the front of the mouth	an adornment worn on the forehead
	a drapery that covers the front of an altar
	the face or front of a building

anterior (adjective)	frontal (adjective)
of or near the head end or toward the front plane of a body	of or relating to the front of an advancing mass of air
earlier in time	meeting front to front
	belonging to the front part
	of or adjacent to the forehead or frontal bone