ephemeron vs insect

ephemeron and insect both are nouns.

Word	Noun	Adjective	Verb	Adverb
ephemeron	Yes	No	No	No
insect	Yes	No	No	No

As nouns, insect is a hypernym of ephemeron; that is, insect is a word with a broader meaning than ephemeron:

ephemeron: anything short-lived, as an insect that lives only for a day in its winged form
insect: small air-breathing arthropod

ephemeron (noun)	insect (noun)
anything short-lived, as an insect that lives only for a day in its winged form	small air-breathing arthropod
	a person who has a nasty or unethical character undeserving of respect