Drug a nice gal's sorted (9)
I believe the answer is:
analgesic
'drug' is the definition.
(analgesic is a kind of drug)
'a nice gal's sorted' is the wordplay.
'sorted' indicates anagramming the letters.
'nice'+'gals'='nicegals'
'nicegals' is an anagram of 'nalgesic'.
'a'+'nalgesic'='ANALGESIC'
(Other definitions for analgesic that I've seen before include "result is soothing" , "Relieving pain" , "Pain-releaving drug" , "number" , "A medicine used to relieve pain" .)