Animal gives party energy (3)
I believe the answer is:
doe
'animal' is the definition.
(a female deer)
'party energy' is the wordplay.
'party' becomes 'do' (do can informally mean a party).
'energy' becomes 'e' (physics symbol as in E=mc2).
'do'+'e'='DOE'
'gives' acts as a link.
(Other definitions for doe that I've seen before include "Female creature" , "She's a deer" , "Last FA Cup winners" , "female of the species" , "Female hare" .)