perfect vs faultless

perfect is a noun but faultless is not a noun.

Word	Noun	Adjective	Verb	Adverb
perfect	Yes	Yes	Yes	No
faultless	No	Yes	No	No

perfect (noun)	faultless (noun)
a tense of verbs used in describing action that has been completed (sometimes regarded as perfective aspect)

perfect (adjective)	faultless (adjective)
being complete of its kind and without defect or blemish	without fault or error
precisely accurate or exact
without qualification; used informally as (often pejorative) intensifiers

perfect (verb)	faultless (verb)
make perfect or complete