impermanent vs transient

impermanent is not a noun while transient is a noun.

Word	Noun	Adjective	Verb	Adverb
impermanent	No	Yes	No	No
transient	Yes	Yes	No	No

impermanent (noun)	transient (noun)
	(physics) a short-lived oscillation in a system caused by a sudden change of voltage or current or load
	one who stays for only a short time

impermanent (adjective)	transient (adjective)
not permanent; not lasting	of a mental act; causing effects outside the mind
existing or enduring for a limited time only	lasting a very short time