ply vs sheet

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. 

sheet

noun
  • A thin, flat layer of solid material. 

  • A layer of veneer. 

  • A piece of paper, usually rectangular, that has been prepared for writing, artwork, drafting, wrapping, manufacture of packaging (boxes, envelopes, etc.), and for other uses. The word does not include scraps and irregular small pieces destined to be recycled, used for stuffing or cushioning or paper mache, etc. 

  • A sail. 

  • A thin bed cloth used as a covering for a mattress or as a layer over the sleeper. 

  • A line (rope) used to adjust the trim of a sail. 

  • The area of ice on which the game of curling is played. 

  • Precipitation of such quantity and force as to resemble a thin, virtually solid wall. 

  • A flat metal pan, often without raised edge, used for baking. 

  • A broad, flat expanse of a material on a surface. 

  • An extensive bed of an eruptive rock intruded between, or overlying, other strata. 

  • The space in the forward or after part of a boat where there are no rowers. 

verb
  • To form into sheets. 

  • Of rain, or other precipitation, to pour heavily. 

  • To cover or wrap with cloth, or paper, or other similar material. 

  • To trim a sail using a sheet. 

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