breakwater vs molehead

breakwater

noun
  • A construction in or around a harbour designed to break the force of the sea and to provide shelter for vessels lying inside. 

  • A wooden or concrete barrier, usually perpendicular to the shore, intended to prevent the movement of sand along a coast. 

  • A low bulkhead across the forecastle deck of a ship which diverts water breaking over the bows into the scuppers. 

molehead

noun
  • A stone bulwark forming a haven or harbour; a breakwater. 

How often have the words breakwater and molehead occurred in a corpus of books? (source: Google Ngram Viewer )