transient vs transeunt

transient is a noun but transeunt is not a noun.

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

As adjectives, transient and transeunt are synonyms defined as:

transient and transeunt: of a mental act; causing effects outside the mind

transient (noun)	transeunt (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)	transeunt (adjective)
of a mental act; causing effects outside the mind	of a mental act; causing effects outside the mind
lasting a very short time