bivalve vs univalve

bivalve and univalve both are nouns.

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

bivalve (noun)	univalve (noun)
marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together	a class of mollusks typically having a one-piece coiled shell and flattened muscular foot with a head bearing stalked eyes

bivalve (adjective)	univalve (adjective)
used of mollusks having two shells (as clams etc.)	used of mollusks, especially gastropods, as snails etc.