univa

a. [ Uni- + L. valens, -entis, p. pr. See Valence. ] (Chem.) Having a valence of one; capable of combining with, or of being substituted for, one atom of hydrogen; monovalent; -- said of certain atoms and radicals. [ 1913 Webster ]

n. [ Uni- + valve: cf. F. univalve. ] (Zool.) A shell consisting of one valve only; a mollusk whose shell is composed of a single piece, as the snails and conchs. [ 1913 Webster ]

☞ Most univalves are spiral and are the shells of gastropods, but many belong to cephalopods and pteropods. A large number of univalves belonging to the gastropods are conical, cup-shaped, or shieldlike, as the limpets. [ 1913 Webster ]

{ } a. [ Cf. F. univalve. ] (Bot. & Zool.) Having one valve; as, a univalve shell or pericarp. [ 1913 Webster ]

‖n. pl. [ NL. ] (Zool.) Same as Gastropoda. [ 1913 Webster ]

a. (Bot. & Zool.) Same as Univalve, a. [ 1913 Webster ]