Ron must produce a remedy (7)
I believe the answer is:
nostrum
'a remedy' is the definition.
(nostrum is a kind of remedy)
'ron must produce' is the wordplay.
'produce' indicates anagramming the letters.
'ron'+'must'='ronmust'
'ronmust' is an anagram of 'NOSTRUM'.
(Other definitions for nostrum that I've seen before include "Quack cure" , "Quack medicine - run most (anag)" , "Must Ron take a quack remedy?" , "Panacea or cure-all" , "Tonic" .)