bollard vs cove

bollard

noun
  • A strong vertical post of timber or iron, fixed to the ground and/or on the deck of a ship, to which the ship's mooring lines etc are secured. 

  • A similar post preventing vehicle access to a pedestrian area, to delineate traffic lanes, or used for security purposes. 

cove

noun
  • A thin line, sometimes gilded, along a yacht's strake below deck level. 

  • A concave vault or archway, especially the arch of a ceiling. 

  • A recess or sheltered area on the slopes of a mountain. 

  • A hollow in a rock; a cave or cavern. 

  • The wooden roof of the stern gallery of an old sailing warship. 

  • A strip of prairie extending into woodland. 

  • A small coastal inlet, especially one having high cliffs protecting vessels from prevailing winds. 

  • A friend; a mate. 

verb
  • To arch over; to build in a hollow concave form; to make in the form of a cove. 

  • To brood, cover, or sit over, as birds their eggs. 

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