1. A cylindrical metal container filled with earth and stones, used in the construction and rerouting of waterways and in flood control.
2. 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.
3. An openwork frame, as of poles, filled with stones and sunk, to assist in forming a bar dyke, etc., as in harbor improvement.

From the Mid-16th century; via French, Italian gabbione "large cage"; gabbia, "cage", from Latin cavea, "hollow".