Plaid is a Scots language word meaning blanket, usually referring to patterned woollen cloth; it is unclear if the Gaelic word Plaide came first. Sometimes, mostly in England, this word is spelled Plad.
- In British English, particularly in Scotland, a plaid or a plaid rug is a large thick woollen twill cloth, often tartan, used as a travel rug or as a blanket. It may be laid on the ground as a tablecloth for a picnic.
- When the modern kilt is worn as a dress uniform, for example by pipe band Drum majors, a plaid is a pleated cloth in the same tartan as the kilt, cast over the shoulder and fastened at the front. A similar plaid in checked cloth was formerly worn by Scottish lowlands shepherds.
- Historically the earlier form of the kilt was the belted plaid, a double width of thick woollen cloth worn pleated and fastened around the waist by a belt, with the upper half often cast over the shoulder but sometimes hanging down over the belt and gathered up at the front or brought up over the head for protection against weather. This was worn over a leine (or shirt) and formed a cheap all-weather outfit that also served as a blanket or bedroll for wild camping. It is mostly associated with the Scottish highlands, but was also used in poor lowland rural areas.
- In American English, plaid is cloth made with alternating stripes and bands of color woven into or dyed onto the fabric. This makes blocks of color that repeat vertically and horizontally in a pattern of squares and lines.
- Plaid is the name of a British electronic music duo, taking their name from the threads of the fabric.
