'Breakwater' definitions:

Definition of 'breakwater'

(from WordNet)
noun
A protective structure of stone or concrete; extends from shore into the water to prevent a beach from washing away [syn: breakwater, groin, groyne, mole, bulwark, seawall, jetty]

Definition of 'Breakwater'

From: GCIDE
  • Breakwater \Break"wa`ter\, n. Any structure or contrivance, as a mole, or a wall at the mouth of a harbor, to break the force of waves, and afford protection from their violence. [1913 Webster]