pure vs vestal

pure is not a noun while vestal is a noun.

Word	Noun	Adjective	Verb	Adverb
pure	No	Yes	No	No
vestal	Yes	Yes	No	No

As adjectives, pure and vestal are synonyms defined as:

Other synonyms of pure include virgin, virginal, virtuous.

pure (noun)	vestal (noun)
	a chaste woman

pure (adjective)	vestal (adjective)
(used of persons or behaviors) having no faults; sinless	of or relating to Vesta
free of extraneous elements of any kind	in a state of sexual virginity
(of color) being chromatically pure; not diluted with white or grey or black
in a state of sexual virginity
free from discordant qualities
concerned with theory and data rather than practice; opposed to applied
without qualification; used informally as (often pejorative) intensifiers