Aide redesigned concept (4)
I believe the answer is:
idea
'concept' is the definition.
(I've seen this in another clue)
'aide redesigned' is the wordplay.
'redesigned' is an anagram indicator.
'aide' is an anagram of 'IDEA'.
(Other definitions for idea that I've seen before include "Mental impression" , "Thought or notion (4)" , "Product of the mind" , "Fancy" , "Clue" .)