The Collaborative International Dictionary of English v.0.48:

Couloir \Cou`loir"\ (k??`lw?r"), n. [F., a strainer.]
   1. A deep gorge; a gully.
      [1913 Webster]

   2. (Hydraul. Engin.) A dredging machine for excavating
      canals, etc.
      [1913 Webster]