'Three-ply' definitions:

Definition of 'three-ply'

From: WordNet
adjective
Having a thickness made up of three layers or strands; "three-ply cloth"; "three-ply yarn"

Definition of 'Three-ply'

From: GCIDE
  • Three-ply \Three"-ply`\, a. Consisting of three distinct webs inwrought together in weaving, as cloth or carpeting; having three strands; threefold. [1913 Webster]