The Collaborative International Dictionary of English v.0.48:

Abalone \Ab`a*lo"ne\ ([a^]b`[.a]*l[=o]"n[-e]), n. (Zool.)
   A univalve mollusk of the genus Haliotis. The shell is
   lined with mother-of-pearl, and used for ornamental purposes;
   the sea-ear. Several large species are found on the coast of
   California, clinging closely to the rocks.
   [1913 Webster]

WordNet (r) 3.0 (2006):

abalone
    n 1: any of various large edible marine gastropods of the genus
         Haliotis having an ear-shaped shell with pearly interior
         [syn: abalone, ear-shell]