A little bird might give the game away (4)
I believe the answer is:
sing
'a little bird' is the definition.
Although both the answer and definition are verbs in their base form, I don't see how one could define the other.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for sing that I've seen before include "Act as informer" , "Croon" , "Inform - carol" , "Vocalise musically" , "pipe" .)