The Collaborative International Dictionary of English v.0.48:

Tuyere \Tu`y[`e]re"\, n. [F.; akin to tuyau a pipe; of Teutonic
   origin. Cf. Tweer, Tewel.]
   A nozzle, mouthpiece, or fixture through which the blast is
   delivered to the interior of a blast furnace, or to the fire
   of a forge. [Corruptly written also tweer, and twier.]
   [1913 Webster]

   Tuy[`e]re arch, the embrasure, in the wall of a blast
      furnace through which the tuy[`e]re enters.
      [1913 Webster]