Gamble a bird might take? (7)

I believe the answer is:

flutter

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'gamble' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for flutter that I've seen before include "Fly unsteadily; small bet" , "Bat" , "Small bet; beat feebly" , "Move one's eyelashes - move like a butterfly - bet" , "Informally a slight gamble as on a horse" .)

I've seen this clue in the Evening Standard.

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