battlement vs rampart

battlement

noun
  • Any high wall for defense. 

  • In fortification: an indented parapet, formed by a series of rising members called cops or merlons, separated by openings called crenelles or embrasures, the soldier sheltering himself behind the merlon while he fires through the embrasure or through a loophole in the battlement. 

  • The towering roof of heaven. 

rampart

noun
  • A defensive structure; a protective barrier; a bulwark. 

  • A defensive mound of earth or a wall with a broad top and usually a stone parapet; a wall-like ridge of earth, stones or debris; an embankment for defensive purpose. 

  • That which defends against intrusion from outside; a protection. 

  • A steep bank of a river or gorge. 

verb
  • To defend with a rampart; fortify or surround with a rampart. 

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