1. 
   Groynes
   Fixed structures extending out from the seawall used to control erosion or promote deposition.
   Found op http://www.encyclo.co.uk/local/20493
   
   
2. 
   groynes
   Low walls built perpendicular to a shoreline to trap sediment, such as sand, drifting along the shore. Groynes are usually made of wood, concrete or piles of large rocks.
   Found op http://www.conservancy.co.uk/learn/wordlist.htm
   
   

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