The Collaborative International Dictionary of English v.0.48:

Anomia \A*no"mi*a\, n. [NL., fr. Gr. ? irregular; 'a priv. +
   no'mos law.] (Zool.)
   A genus of bivalve shells, allied to the oyster, so called
   from their unequal valves, of which the lower is perforated
   for attachment.
   [1913 Webster]

WordNet (r) 3.0 (2006):

anomia
    n 1: inability to name objects or to recognize written or spoken
         names of objects [syn: nominal aphasia, anomic aphasia,
         anomia, amnesic aphasia, amnestic aphasia]
    2: type genus of the family Anomiidae: saddle oysters [syn:
       Anomia, genus Anomia]