Cloth cut from seam on the counter (5)
I believe the answer is:
denim
'cloth' is the definition.
(denim is a kind of cloth)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for denim that I've seen before include "Hard-wearing blue fabric" , "Material for casual trousers or jackets" , "Cotton twill fabric" , "Mined badly for a hard-wearing fabric" , "Coloured cotton twill" .)