posts vs rampart

posts

rampart

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

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