1) Barrier 2) Breakwater 3) Bulwark 4) French word used in English 5) Groin 6) Jetty 7) Mole 8) Seawall 1) Breakwater 2) Jetty 3) Seawall 
A groyne (groin in the United States) is a rigid hydraulic structure built from an ocean shore (in coastal engineering) or from a bank (in rivers) that interrupts water flow and limits the movement of sediment. In the ocean, groynes create beaches, or prevent them being washed away by longshore drift. In a river, groynes prevent erosion and ice-ja...
wooden breakwater
• (n.) See Groin.
A projecting (often wooden) structure to stop sand shifting along a beach.
Groyne noun [ Obsolete] See Groin . 
Groyne is British slang for a diamond ring.
Wooden or concrete barrier built at right angles to a beach in order to block the movement of material along the beach by longshore drift. Groynes are usually successful in protecting individual beaches, but because they prevent beach material from passing along the coast they can mean that other beaches, starved of sand and shingle, are in danger ...