Garment in this fashion has designer label (4)
I believe the answer is:
sock
'garment' is the definition.
(I know that sock is a type of hosiery)
'in this fashion has designer label' is the wordplay.
'in this fashion' becomes 'so' (I can't explain this - if you can you should give a lot more credence to this answer).
'has' says to put letters next to each other.
'designer label' becomes 'ck' (Calvin Klein).
'so'+'ck'='SOCK'
Can you help me to learn more?
(Other definitions for sock that I've seen before include "Item of footwear" , "Hit forcefully; footwear" , "Hit; horse's leg marking" , "impact" , "Clothing; punch" .)