unoriginal vs original

unoriginal is not a noun while original is a noun.

Word	Noun	Adjective	Verb	Adverb
unoriginal	No	Yes	No	No
original	Yes	Yes	No	No

unoriginal (noun)	original (noun)
	an original creation (i.e., an audio recording) from which copies can be made
	something that serves as a model or a basis for making copies

unoriginal (adjective)	original (adjective)
not original; not being or productive of something fresh and unusual	being or productive of something fresh and unusual; or being as first made or thought of
	(of e.g. information) not secondhand or by way of something intermediary
	not derived or copied or translated from something else
	preceding all others in time or being as first made or performed