DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   clapper
       n 1: someone who applauds [syn: clapper, applauder]
       2: a mobile mass of muscular tissue covered with mucous membrane
          and located in the oral cavity [syn: tongue, lingua,
          glossa, clapper]
       3: metal striker that hangs inside a bell and makes a sound by
          hitting the side [syn: clapper, tongue]