escarpment vs scarp

escarpment

noun
  • A steep descent or declivity; steep face or edge of a ridge; ground about a fortified place, cut away nearly vertically to prevent hostile approach. 

scarp

noun
  • A cliff at the edge of a plateau or ridge caused by erosion or faulting; the steeper side of an escarpment. 

  • The steep artificial slope below a fort's parapet. 

verb
  • to cut, scrape, erode, or otherwise make into a scarp or escarpment 

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