Christopher E Bird (4)
I believe the answer is:
kite
'bird' is the definition.
(kite is a kind of bird)
'christopher e' is the wordplay.
'christopher' becomes 'kit' (I've seen this in other clues).
'kit'+'e'='KITE'
(Other definitions for kite that I've seen before include "One's flown" , "Kind of toy flown on string" , "Bird of prey - light, wind-borne structure" , "Soaring bird of prey" , "It flies with string attached" .)