Fruit gives ape energy (6)
I believe the answer is:
orange
'fruit' is the definition.
(orange is a kind of fruit)
'ape energy' is the wordplay.
'ape' becomes 'orang' (orang is a kind of ape).
'energy' becomes 'e' (physics symbol as in E=mc2).
'orang'+'e'='ORANGE'
'gives' is the link.
(Other definitions for orange that I've seen before include "One's pipped" , "network" , "Colour of an onager?" , "Go earn the fruit" , "Loyalist colour" .)