ephemeral vs transient

ephemeral and transient both are nouns.

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

As adjectives, ephemeral and transient are synonyms defined as:

Other synonyms of ephemeral include fugacious, passing, short-lived, transitory.

ephemeral (noun)	transient (noun)
anything short-lived, as an insect that lives only for a day in its winged form	(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

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