Gasteropoda vs univalve

Gasteropoda and univalve both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gasteropoda	Yes	No	No	No
univalve	Yes	Yes	No	No

Gasteropoda (noun)	univalve (noun)
snails and slugs and their relatives	a class of mollusks typically having a one-piece coiled shell and flattened muscular foot with a head bearing stalked eyes

Gasteropoda (adjective)	univalve (adjective)
	used of mollusks, especially gastropods, as snails etc.