layer vs ply

layer

noun
  • A single thickness of some material covering a surface. 

  • One of the items in a hierarchy. 

  • A person who lays anything, such as tiles or a wager. 

  • A (usually) horizontal deposit; a stratum. 

  • A shoot of a plant, laid underground for growth. 

  • An item of clothing worn under or over another. 

  • A mature female bird, insect, etc. that is able to lay eggs. 

  • A hen kept to lay eggs. 

  • one in a stack of (initially transparent) drawing surfaces that comprise an image; used to keep elements of an image separate so that they can be modified independently from one another. 

verb
  • To arrange in layers. 

  • To cut or divide into layers. 

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. 

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