transient vs impermanent

transient is a noun but impermanent is not a noun.

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

transient (noun)	impermanent (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

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