Tartan (5)
I believe the answer is:
plaid
'tartan' is the definition.
(I know that tartan can be written as plaid)
This is the entire clue.
(Other definitions for plaid that I've seen before include "Tartan patterned cloth" , "Tartan-pattern cloth" , "Scottish Highland fabric" , "party in Wales" , "Scotsman's cloth" .)