freeboard vs rampart

freeboard

noun
  • The distance between a water level and the top of something that contains or restrains it (such as a dam). 

  • The distance between the top of sea ice and the water level. 

  • A type of skateboard which simulates the movement of a snowboard when used on a downhill coarse, allowing snowboarding techniques, which has an addition of two centerline casters that extend below the traditional skateboard wheels and bogies. 

  • The vertical distance between the waterline and the uppermost watertight deck of a vessel. 

rampart

noun
  • A steep bank of a river or gorge. 

  • 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. 

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

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