A drug that relieves pain (7)
I believe the answer is:
anodyne
'a drug that relieves pain' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for anodyne that I've seen before include "Describes what soothes or dulls the senses" , "Causing no offence" , "Painkilling (medicine)" , "Soothing to the mind or feelings" , "Innocent" .)