The Collaborative International Dictionary of English v.0.48:

Genouillere \Ge*nouil`l[`e]re"\, n. [F.]
   1. (Anc. Armor) A metal plate covering the knee.
      [1913 Webster]

   2. (Fort.) That part of a parapet which lies between the gun
      platform and the bottom of an embrasure.
      [1913 Webster]