mound vs washboard

mound

verb
  • To force or pile into a mound or mounds. 

  • To form a mound. 

  • To fortify with a mound; add a barrier, rampart, etc. to. 

noun
  • The mons veneris. 

  • Elevated area of dirt upon which the pitcher stands to pitch. 

  • A natural elevation appearing as if thrown up artificially; a regular and isolated hill, hillock, or knoll. 

  • A ball or globe forming part of the regalia of an emperor or other sovereign. It is encircled with bands, enriched with precious stones, and surmounted with a cross. 

  • An artificial hill or elevation of earth; a raised bank; an embankment thrown up for defense 

washboard

verb
  • To move up and down or back and forth across the surface of a hive, possibly to lay down a layer of propolis and wax. 

  • To play a washboard. 

  • To produce a rippled texture on a surface. 

noun
  • A stretch of ripples or bumps on a dirt or gravel road caused by interaction between traffic and road surface. 

  • A board fastened along a ship's gunwale to prevent splashing; a splashboard. 

  • Such a board used as a simple percussion instrument. 

  • A board with a corrugated surface against which laundry may be rubbed. 

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