sea wall

a strong wall or embankment to prevent the encroachments of the sea, serve as a breakwater, etc.

Origin of sea wall

before 1000; Middle English; Old English: cliff over the sea

sea-walled, adjective

Some fishermen on the beach were talking to two women with red handkerchiefs on their heads, who were leaning over the sea-wall.

Mentone, Cairo, and Corfu |Constance Fenimore Woolson
Instead of blowing, he raised a gale only by flapping his cloak; and the water rose behind us in a sea-wall.

The Vinland Champions |Ottilie A. Liljencrantz
The harbour is protected by a sea-wall built along the low-water line, and an iron pier affords accommodation for large vessels.

Encyclopaedia Britannica, 11th Edition, Volume 16, Slice 6 |Various
We saw several in course of construction on the small recessed slips which indented the sea-wall of the island.

Cruise of the 'Alert' |R. W. Coppinger

Presently the boat grounded on some rocks at the foot of the sea-wall, which rose high above them.

Vine and Olive; Or Young America in Spain and Portugal |Oliver Optic

sea wall

a wall or embankment built to prevent encroachment or erosion by the sea or to serve as a breakwater

sea-walled, adjective