The term 'Beach Barrier' can be broken down into two crossword solutions: GROYNE (6 letters) and DUNE (4 letters). A GROYNE is a structure built from wood, concrete, or stone that is placed in the ocean to protect beaches from erosion. A DUNE is a hill of sand that is formed by wind and is often found near beaches. Both groynes and dunes act as barriers to protect beaches from erosion and other environmental changes.