valve vs valvular

valve is a noun but valvular is not a noun.

Word	Noun	Adjective	Verb	Adverb
valve	Yes	No	No	No
valvular	No	Yes	No	No

valve (noun)	valvular (noun)
one of the paired hinged shells of certain molluscs and of brachiopods
the entire one-piece shell of a snail and certain other molluscs
control consisting of a mechanical device for controlling the flow of a fluid
device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it

valve (adjective)	valvular (adjective)
	relating to or operating by means of valves