ephemeral vs transitory

ephemeral is a noun but transitory is not a noun.

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

As adjectives, ephemeral and transitory are synonyms defined as:

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

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

ephemeral (adjective)	transitory (adjective)
lasting a very short time	lasting a very short time