The Collaborative International Dictionary of English v.0.48:

Kiln \Kiln\ (k[i^]ln or k[i^]l), n. [OE. kilne, kulne, AS. cyln,
   cylen; akin to Icel. kylna; prob. from the same source as
   coal. See Coal.]
   1. A large stove or oven; a furnace of brick or stone, or a
      heated chamber, for the purpose of hardening, burning, or
      drying anything; as, a kiln for baking or hardening
      earthen vessels; a kiln for drying grain, meal, lumber,
      etc.; a kiln for calcining limestone.
      [1913 Webster]

   2. A furnace for burning bricks; a brickkiln.
      [1913 Webster]

WordNet (r) 3.0 (2006):

kiln
    n 1: a furnace for firing or burning or drying such things as
         porcelain or bricks