A place in which man's pains may be alleviated (3)
I believe the answer is:
spa
'a place in which man's pains may be alleviated' is the definition.
'spa' can be an answer for 'a place' (I have seen 'place of treatment' mean 'spa' so perhaps 'place' could also mean 'spa'). I am unsure of the remainder of the definition.
'a place in which man's pains' is the wordplay.
'a place in' indicates a hidden word (I've seen 'placed in' mean this).
'SPA' is hidden within 'which ns pains'.
Can you help me to learn more?
(Other definitions for spa that I've seen before include "Watering place" , "Curative resort" , "town in Belgium" , "town for his health!" , "Cheltenham or Bath?" .)