The Collaborative International Dictionary of English v.0.48:

Strombus \Strom"bus\, n. [L., fr. Gr. ?.] (Zool.)
   A genus of marine gastropods in which the shell has the outer
   lip dilated into a broad wing. It includes many large and
   handsome species commonly called conch shells, or conchs.
   See Conch.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Strombus
    n 1: type genus of the family Strombidae [syn: Strombus,
         genus Strombus]