Small game bird (5)
I believe the answer is:
quail
'small game bird' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for quail that I've seen before include "Show fear - of small game bird?" , "Game bird - cower" , "Flinch from small gamebird?" , "Cower before the game-bird?" , "Shrink; a bird" .)