Belt in this fashion designer's label (4)
I believe the answer is:
sock
'belt' is the definition.
(both can mean to hit)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for sock that I've seen before include "Hit; horse's leg marking" , "Hit; garment" , "Clothing; punch" , "Hit forcefully; footwear" , "bash" .)