glowworm vs firefly

glowworm and firefly both are nouns.

Word	Noun	Adjective	Verb	Adverb
glowworm	Yes	No	No	No
firefly	Yes	No	No	No

As nouns, firefly is a hypernym of glowworm; that is, firefly is a word with a broader meaning than glowworm:

glowworm: the luminous larva or wingless grub-like female of a firefly
firefly: nocturnal beetle common in warm regions having luminescent abdominal organs

Other hypernyms of glowworm include lightning bug.

glowworm (noun)	firefly (noun)
the luminous larva or wingless grub-like female of a firefly	nocturnal beetle common in warm regions having luminescent abdominal organs
	tropical American click beetle having bright luminous spots