Aide contrived a plan (4)
I believe the answer is:
idea
'a plan' is the definition.
(both can mean an intention)
'aide contrived' is the wordplay.
'contrived' is an anagram indicator.
'aide' is an anagram of 'IDEA'.
(Other definitions for idea that I've seen before include "Content of cognition" , "Notion in the mind" , "Fancy" , "Product of the mind" , "Intention" .)