Dicky can then charm (7)
I believe the answer is:
enchant
'charm' is the definition.
(I know that charm can be written as enchant)
'dicky can then' is the wordplay.
'dicky' indicates an anagram (dicky can mean ill or non-functioning).
'can'+'then'='canthen'
'canthen' is an anagram of 'ENCHANT'.
(Other definitions for enchant that I've seen before include "Bewitch, charm" , "Hypnotise" , "Beguile" , "Captivate, charm" , "Delight or bewitch" .)