ad-lib vs unscripted

ad-lib is a noun but unscripted is not a noun.

Word	Noun	Adjective	Verb	Adverb
ad-lib	Yes	Yes	Yes	No
unscripted	No	Yes	No	No

ad-lib (noun)	unscripted (noun)
remark made spontaneously without prior preparation

ad-lib (adjective)	unscripted (adjective)
with little or no preparation or forethought	not furnished with or using a script
said or done without having been planned or written in advance

ad-lib (verb)	unscripted (verb)
perform without preparation