The Collaborative International Dictionary of English v.0.48:

Palisade \Pal`i*sade"\, n. [F. palissade, cf. Sp. palizada, It.
   palizzata, palizzo, LL. palissata; all fr. L. palus a stake,
   pale. See Pale a stake.]
   1. (Fort.) A strong, long stake, one end of which is set
      firmly in the ground, and the other is sharpened; also, a
      fence formed of such stakes set in the ground as a means
      of defense.
      [1913 Webster]

   2. Any fence made of pales or sharp stakes.
      [1913 Webster]

   3. A line of bold cliffs, esp. one showing basaltic columns;
      -- usually in pl., and orig. used as the name of the
      cliffs on the west bank of the lower Hudson.
      [Webster 1913 Suppl.]

   Palisade cells (Bot.), vertically elongated parenchyma
      cells, such as are seen beneath the epidermis of the upper
      surface of many leaves.

   Palisade worm (Zool.), a nematoid worm (Strongylus
      armatus), parasitic in the blood vessels of the horse, in
      which it produces aneurisms, often fatal.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Palisade \Pal`i*sade"\, v. t. [imp. & p. p. Palisaded; p. pr.
   & vb. n. Palisading.] [Cf. F. palissader.]
   To surround, inclose, or fortify, with palisades.
   [1913 Webster]

WordNet (r) 3.0 (2006):

palisade
    n 1: fortification consisting of a strong fence made of stakes
         driven into the ground
    v 1: surround with a wall in order to fortify [syn: wall,
         palisade, fence, fence in, surround]