knap vs windrow

knap

noun
  • The crest of a hill 

  • A protuberance; a swelling; a knob. 

  • A small hill 

  • A sharp blow or slap. 

verb
  • To rap or strike sharply. 

  • To shape a brittle material having conchoidal fracture, usually a mineral (flint, obsidian, chert etc.), by breaking away flakes, often forming a sharp edge or point. 

  • To make a sound of snapping. 

windrow

noun
  • A ridge or berm at a perimeter 

  • The green border of a field, dug up in order to carry the earth onto other land to improve it. 

  • A line of snow left behind by the edge of a snowplow’s blade. 

  • A long snowbank along the side of a road. 

  • A line of leaves etc heaped up by the wind. 

  • A similar streak of seaweed etc on the surface of the sea formed by Langmuir circulation. 

  • A line of gravel left behind by the edge of a grader’s blade. 

  • A row of cut grain or hay allowed to dry in a field. 

verb
  • To arrange (e.g. new-made hay) in lines or windrows. 

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