Detest being without energy to box (8)
I believe the answer is:
execrate
'detest' is the definition.
(execrating is a kind of detesting)
'without energy to box' is the wordplay.
'without' becomes 'ex' (I've seen this in other clues**).
'energy' becomes 'e' (physics symbol as in E=mcx).
'to box' becomes 'crate' (crate is a kind of box).
'ex'+'e'+'crate'='EXECRATE'
'being' is the link.
(Other definitions for execrate that I've seen before include "hate" , "Inveigh against" , "Express great loathing for" , "Utter curses with erect axe" , "Curse" .)