Consider aiming energy contrivance (7)
I believe the answer is:
imagine
'consider' is the definition.
(thesaurus)
'aiming energy contrivance' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mc2).
'contrivance' indicates anagramming the letters.
'aiming'+'e'='aiminge'
'aiminge' is an anagram of 'IMAGINE'.
(Other definitions for imagine that I've seen before include "See something that doesn't exist" , "Suppose; think up" , "Picture, conceive" , "Suspect" , "Reckon" .)