Multivalve \Mul"ti*valve\, n. [Cf. F. multivalve.] (Zo["o]l.) Any mollusk which has a shell composed of more than two pieces. Multivalve \Mul"ti*valve\, Multivalvular \Mul`ti*val"vu*lar\, a. [Multi- + valve, valvular: cf. F. multivalve.] 1. Having many valves. 2. (Zo["o]l.) Many-valved; having more than two valves; -- said of certain shells, as the chitons.