The Collaborative International Dictionary of English v.0.48:

Bema \Be"ma\, n. [Gr. ? step, platform.]
   [1913 Webster]
   1. (Gr. Antiq.) A platform from which speakers addressed an
      assembly. --Mitford.
      [1913 Webster]

   2. (Arch.)
      (a) That part of an early Christian church which was
          reserved for the higher clergy; the inner or eastern
          part of the chancel.
      (b) Erroneously: A pulpit.
          [1913 Webster]

WordNet (r) 3.0 (2006):

bema
    n 1: area around the altar of a church for the clergy and choir;
         often enclosed by a lattice or railing [syn: chancel,
         sanctuary, bema]