General prepared to expatiate (7)
I believe the answer is:
enlarge
'to expatiate' is the definition.
(I've seen this before)
'general prepared' is the wordplay.
'prepared' indicates an anagram.
'general' with letters rearranged gives 'ENLARGE'.
(Other definitions for enlarge that I've seen before include "Expand" , "Stretch" , "Make bigger in general" , "go into greater detail" , "Expatiate" .)