idle vs unwarranted

idle is a noun but unwarranted is not a noun.

Word	Noun	Adjective	Verb	Adverb
idle	Yes	Yes	Yes	No
unwarranted	No	Yes	No	No

As adjectives, idle and unwarranted are synonyms defined as:

Other synonyms of idle include baseless, groundless, unfounded, wild.

idle (noun)	unwarranted (noun)
the state of an engine or other mechanism that is idling

idle (adjective)	unwarranted (adjective)
not in action or at work	incapable of being justified or explained
silly or trivial	lacking justification or authorization
not in active use	without a basis in reason or fact
lacking a sense of restraint or responsibility
not having a job
not yielding a return
without a basis in reason or fact

idle (verb)	unwarranted (verb)
run disconnected or idle
be idle; exist in a changeless situation