Bird used kinetic energy containing it (4)
I believe the answer is:
kite
'bird' is the definition.
(kite is a kind of bird)
'kinetic energy containing it' is the wordplay.
'kinetic energy' becomes 'ke' ('K.E.' can be a synonym of 'kinetic energy').
'containing' is an insertion indicator.
'ke' going around 'it' is 'KITE'.
'used' is the link.
(Other definitions for kite that I've seen before include "Toy that flies on end of string" , "Light frame toy held on a string - bird of prey" , "Bird of prey and flying toy" , "Winger" , "flyer" .)