Source : Webster's Revised Unabridged Dictionary (1913)

Gemara \Ge*ma"ra\, n. [Heb.] (Jewish Law)
   The second part of the Talmud, or the commentary on the
   Mishna (which forms the first part or text).

Source : WordNet®

Gemara
     n : the second part of the Talmud consisting primarily of
         commentary on the Mishna