Source : Webster's Revised Unabridged Dictionary (1913)

Plaid \Plaid\, n. [Gael. plaide a blanket or plaid, contr. fr.
   peallaid a sheepskin, fr. peall a skin or hide. CF.
   {Pillion}.]
   1. A rectangular garment or piece of cloth, usually made of
      the checkered material called tartan, but sometimes of
      plain gray, or gray with black stripes. It is worn by both
      sexes in Scotland.

   2. Goods of any quality or material of the pattern of a plaid
      or tartan; a checkered cloth or pattern.

Plaid \Plaid\, a.
   Having a pattern or colors which resemble a Scotch plaid;
   checkered or marked with bars or stripes at right angles to
   one another; as, plaid muslin.

Source : WordNet®

plaid
     n : a cloth having a crisscross design [syn: {tartan}]