shield vs washboard

shield

noun
  • Parts at the front and back of a vehicle which are meant to absorb the impact of a collision 

  • A large expanse of exposed stable Precambrian rock. 

  • A wide and relatively low-profiled volcano, usually composed entirely of lava flows. 

  • A broad piece of defensive armor, held in hand, formerly in general use in war, for the protection of the body. 

  • One who protects or defends. 

  • A spot resembling, or having the form of a shield. 

  • A sign or symbol, usually containing numbers and sometimes letters, identifying a highway route. 

  • A framework used to protect workmen in making an adit under ground, and capable of being pushed along as excavation progresses. 

  • The escutcheon or field on which are placed the bearings in coats of arms. 

  • A field of energy that protects or defends. 

  • In lichens, a hardened cup or disk surrounded by a rim and containing the fructification, or asci. 

  • A police badge. 

verb
  • To protect, to defend. 

  • to protect from the influence of 

  • To shelter; to protect oneself. 

washboard

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. 

verb
  • To play a washboard. 

  • 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 produce a rippled texture on a surface. 

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