Source : Webster's Revised Unabridged Dictionary (1913)

Frit \Frit\, n. [F. fritte, fr. frit fried, p. p. of frire to
   fry. See {Far}, v. t.]
   1. (Glass Making) The material of which glass is made, after
      having been calcined or partly fused in a furnace, but
      before vitrification. It is a composition of silex and
      alkali, occasionally with other ingredients. --Ure.

   2. (Ceramics) The material for glaze of pottery.

   {Frit brick}, a lump of calcined glass materials, brought to
      a pasty condition in a reverberatory furnace, preliminary
      to the perfect vitrification in the melting pot.