Definition of plaids:
(n) :
(textiles) A type of twilled woollen cloth, often with a tartan or chequered pattern.
(n) :
The typical chequered pattern of a plaid; tartan.
(adj) :
Having a pattern or colors which resemble a Scottish tartan; checkered or marked with bars or stripes at right angles to one another.
(n) :
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.
(n) :
Short for Plaid Cymru. [A Welsh political party, committed to Welsh independence from the United Kingdom.]