barbican vs palisade

barbican

noun
  • A temporary wooden tower built for defensive purposes. 

  • An opening in the wall of a fortress through which the guns are levelled; a narrow loophole through which arrows and other missiles may be shot. 

  • A tower at the entrance to a castle or fortified town 

  • A fortress at the end of a bridge. 

palisade

noun
  • A wall of wooden stakes, used as a defensive barrier. 

  • An even row of cells. e.g.: palisade mesophyll cells. 

  • A line of cliffs, especially one showing basaltic columns. 

  • A long, strong stake, one end of which is set firmly in the ground, and the other sharpened. 

verb
  • To equip with a palisade. 

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