Tartan trousers (5)
I believe the answer is:
trews
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tartan trousers</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for trews that I've seen before include "Trousers of a Scot" , "Garment" , "Wrest (anag) - trousers" , "nether garments" , "close-fitting garments" .)