- a thickness or layer of a folded or laminated material；a strand of yarn or rope
noun: ply, plural noun: plies
- 1. a thickness or layer of a folded or laminated material tiles that have a black PVC ply in the lamination
- ▪ a strand of yarn or rope 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
- ▪ a reinforcing layer of fabric in a tyre a six-ply whitewall tire
- 2. short for plywood
- 3. (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.
- ▪ a half-move (i.e. one player's move) in computer chess.