ply1

 
Pronunciation: /plʌɪ/

noun (plural plies)

  • 1a thickness or layer of a folded or laminated material: tiles that have a black PVC ply in the lamination
  • [usually in combination] a strand of yarn or rope: [as modifier]: four-ply yarn
  • the number of multiple layers or strands of which something is made: the yarn can be any ply from two to eight
  • 3 [mass noun] (in game theory) the number of levels at which branching occurs in a tree of possible outcomes, typically corresponding to the number of moves ahead (in chess strictly half-moves ahead) considered by a computer program.
  • [count noun] a half-move (i.e. one player’s move) in computer chess.

Origin:

late Middle English (in the sense 'fold'): from French pli 'fold', from the verb plier, from Latin plicare 'to fold'