ply 1 (plī)
tr.v. plied (plīd), ply·ing, plies (plīz)
1. To join together, as by molding or twisting.
2. To double over (cloth, for example).
n. pl. plies (plīz)
1. A layer, as of doubled-over cloth or of paperboard.
2. One of the sheets of wood glued together to form plywood.
3. A layer of rubber-coated fabric, often of nylon or polyester cords, forming the body of an automobile tire.
4. One of the strands twisted together to make yarn, rope, or thread. Often used in combination: three-ply cord.
5. A bias; an inclination.
[Middle English plien, from Old French plier, alteration of pleier, from Latin plicāre, to fold; see plek- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.