means A pattern of crisscrossing horizontal and vertical bands in multiple colors, especially as woven into cloth like tartan.

from From Scottish Gaelic 'plaide,' meaning a blanket or cloak — the large woolen wrap a Highlander would drape over the shoulder. In Scots usage the word named the garment first; English later borrowed it and slid the meaning onto the checked pattern the cloth so often wore. The deeper root of 'plaide' is uncertain, though it's sometimes linked to 'peallaid,' a sheepskin — fitting, for a word that began as something you wore against the weather before it became something you simply wore.