Scottish plaid (6)
I believe the answer is:
tartan
'scottish plaid' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tartan that I've seen before include "Pattern of the Scottish clans" , "(Fabric with) distinctive checked pattern" , "Woollen checked material" , "Distinctive cloth pattern of a Highlands clan" , "Scottish woollen cloth" .)