The Collaborative International Dictionary of English v.0.48:

Gabion \Ga"bi*on\, n.[F., from It. gabbione a large cage,
   gabion, from gabbia cage, L. cavea. See Cage.]
   1. (Fort.) A hollow cylinder of wickerwork, like a basket
      without a bottom. Gabions are made of various sizes, and
      filled with earth in building fieldworks to shelter men
      from an enemy's fire.
      [1913 Webster]

   2. (Hydraul. Engin.) An openwork frame, as of poles, filled
      with stones and sunk, to assist in forming a bar dyke,
      etc., as in harbor improvement.
      [1913 Webster]