Overalls material (5)
I believe the answer is:
denim
'overalls material' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for denim that I've seen before include "Fabric used for jeans" , "Twilled cotton fabric" , "Tough cotton fabric" , "Mined badly for a hard-wearing fabric" , "Material for casual trousers or jackets" .)