Garment for one who perspires (7)
I believe the answer is:
sweater
'garment' is the definition.
(I know that sweater is a type of garment)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for sweater that I've seen before include "Knitted upper garment" , "person in a sauna?" , "A present from Mum!" , "Long-sleeved pullover" , "Jumper (7)" .)