Dance with energy and desire (4)
I believe the answer is:
hope
'desire' is the definition.
('hope' can be a synonym of 'desire')
'dance with energy' is the wordplay.
'dance' becomes 'hop' (hop is a kind of dance**).
'with' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mco).
'hop'+'e'='HOPE'
'and' is the link.
(Other definitions for hope that I've seen before include "Feeling of expectation or desire" , "Confident expectation" , "combination of expectation and desire" , "It alone stayed in Pandora's box" , "Trustful expectation" .)