Source : Webster's Revised Unabridged Dictionary (1913)

Gatch \Gatch\, n. [Per. gach mortar.]
   Plaster as used in Persian architecture and decorative art.

   {Gatch decoration}, decoration in plaster often producing
      design of great beauty.

   {Gatch work}, work in which gatch is employed; also, articles
      of gatch ornamentation collectively.