DuckCorp Dico

Found one definition

1.                 From The Collaborative International Dictionary of English v.0.48:
                   
   
   
                   
                     
   Concha \Con"cha\ (k[o^][ng]"k[.a]), n. [LL. (in sense 1), fr. L.
      concha. See Conch.]
      1. (Arch.) The plain semidome of an apse; sometimes used for
         the entire apse.
         [1913 Webster]
      2. (Anat.) The external ear; esp. the largest and deepest
         concavity of the external ear, surrounding the entrance to
         the auditory canal.
         [1913 Webster]