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.
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.