Jeans fabric (5)
I believe the answer is:
denim
'jeans fabric' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for denim that I've seen before include "Hard-wearing blue fabric" , "Durable material" , "Mined (anag)" , "Coloured cotton twill" , "Material for casual trousers or jackets" .)