From Scots plaid, of uncertain origin; perhaps from a past participle form of ply.

Also compare Scottish Gaelic peall << Latin pellis, but the OED finds the sound changes problematic.

• (Scotland) IPA: /pled/, /plad/
• (British, RP, America) IPA: /plæd/

plaid

1. (textiles) A type of twilled woollen cloth, often with a tartan or chequered pattern. [from 16^thc.]
   • 1906, Stanley J[ohn] Weyman, chapter I, in Chippinge Borough, New York, N.Y.: McClure, Phillips & Co., →OCLC ↗, page 01 ↗:

     It was April 22, 1831, and a young man was walking down Whitehall in the direction of Parliament Street. He wore shepherd's plaid trousers and the swallow-tail coat of the day, with a figured muslin cravat wound about his wide-spread collar.

2. A length of such material used as a piece of clothing, formerly worn in the Scottish Highlands and other parts of northern Britain and remaining as an item of ceremonial dress worn by members of Scottish pipe bands. [from 16^thc.]
3. The typical chequered pattern of a plaid; tartan. [from 19^thc.]

• French: tissu écossais
• Russian: плед
• Spanish: tela escocesa

• French: plaid
• German: Plaid, Schulerdecke, Umhangtuch
• Russian: плед

• French: motif écossais
• German: Schottenstoff, Schottenmuster
• Russian: кле́тчатый
• Spanish: cuadros escoceses, cuadrillé

plaid

1. Having a pattern or colors which resemble a Scottish tartan; checkered or marked with bars or stripes at right angles to one another.

Alternative forms.

1. (archaic) Simple past tense and past participle of play
   • 1774, Dr Samuel Johnson, Preface to the Works of the English Poets, J. Nichols, Volume II, Page 134,

     "...then plaid on the organ, and sung..."