Muffle

n.
  1. Anything with which another thing, as an oar or drum, is muffled; also, a boxing glove; a muff.
  2. (Metal.) An earthenware compartment or oven, often shaped like a half cylinder, used in furnaces to protect objects heated from the direct action of the fire, as in scorification of ores, cupellation of ore buttons, etc.
  3. (Ceramics) A small oven for baking and fixing the colors of painted or printed pottery, without exposing the pottery to the flames of the furnace or kiln.
  4. A pulley block containing several sheaves.