safety vs washboard

safety

noun
  • A safety squeeze. 

  • An instance of a player being sacked or tackled in the end zone, or stepping out of the end zone and off the field, resulting in two points to the opposite team. 

  • A mechanism on a weapon or dangerous equipment designed to prevent accidental firing. 

  • The condition or feeling of being safe; security; certainty. 

  • Any of the defensive players who are in position furthest from the line of scrimmage and whose responsibility is to defend against passes as well as to be the tacklers of last resort. 

  • Preservation from escape; close custody. 

verb
  • to secure a firing pin, as in guns, to keep the gun from firing 

  • To secure (a mechanical component, as in aviation) to keep it from becoming detached even under vibration. 

washboard

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

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

  • 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 safety and washboard occurred in a corpus of books? (source: Google Ngram Viewer )