berm vs shelf

berm

noun
  • A narrow ledge or shelf, as along the top or bottom of a slope. 

  • A raised bank or path, especially the bank of a canal opposite the towpath. 

  • A mound or bank of earth, used especially as a barrier or to provide insulation. 

  • A terrace formed by wave action along a beach. 

  • A strip of land between a street and sidewalk. 

  • A ledge between the parapet and the moat in a fortification. 

  • Edge of a road. 

verb
  • To provide something with a berm 

shelf

noun
  • A projecting ledge that resembles such an object. 

  • A reef, shoal or sandbar. 

  • The part of a repository where shelvesets are stored. 

  • A flat, rigid structure, fixed at right angles to a wall or forming a part of a cabinet, desk etc., and used to support, store or display objects. 

  • The capacity of such an object 

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