Admitted moving down with energy (5)
I believe the answer is:
owned
'admitted' is the definition.
(own can mean to admit or acknowledge)
'moving down with energy' is the wordplay.
'moving' is an anagram indicator (letters are moved around).
'with' means one lot of letters goes inside another.
'energy' becomes 'e' (physics symbol as in E=mc2).
'down' is an anagram of 'ownd'.
'ownd' going around 'e' is 'OWNED'.
(Other definitions for owned that I've seen before include "Possessed; admitted" , "Had possession of" , "to oneself?" , "Had lawful title to" , "Confessed" .)