ply vs thickness

ply

noun
  • A layer of material. 

  • In two-player sequential games, a "half-turn" or a move made by one of the players. 

  • A bent; a direction. 

  • A strand that, twisted together with other strands, makes up rope or yarn. 

  • A condition, a state. 

verb
  • To work at (something) diligently. 

  • To press upon; to urge persistently. 

  • To persist in offering something to, especially for the purpose of inducement or persuasion. 

  • To travel over (a route) regularly. 

  • To bend, to flex; to be bent by something, to give way or yield (to a force, etc.). 

  • To wield or use (a tool, a weapon, etc.) steadily or vigorously. 

thickness

noun
  • A layer. 

  • A measure of how thick (in dimension) something is. 

  • The quality of being thick (in consistency). 

  • The property of being thick (slow to understand). 

  • The property of being thick (in dimension). 

verb
  • To trim (wood) to a consistent thickness using a thickness planer. 

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