Glacis

The foam of these great ruins mounts in an instant to the ridge of the sand glacis, swiftly fleets back again, and is met and buried by the next breaker.

[T]ook his place with solemn / Air 'midst the rest, who kept their valiant faces / And levelled weapons still against the glacis.

[T]heir hearts had failed them at the silence and the blaze of lighted ships from end to end of the harbour, with eerie beams of the searchlights revealing the bleakness of the glacis they would have to cross.