Winger is kid on edge (9)
I believe the answer is:
chaffinch
'winger' is the definition.
(chaffinch is a kind of bird)
'kid on edge' is the wordplay.
'kid' becomes 'chaff' (synonyms).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'edge' becomes 'inch' (as in edging or inching along).
'chaff'+'inch'='CHAFFINCH'
'is' acts as a link.
(Other definitions for chaffinch that I've seen before include "Small European songbird" , "Singer" , "Common bird" , "flier" , "European bird with black and white wings" .)