Time in jail? It can fly! (4)

I believe the answer is:

bird

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'time' is the definition.
(both are slang for a prison sentence)

I cannot understand how the rest of the clue works.

(Other definitions for bird that I've seen before include "Dawn chorus etc - book by Sebastian Faulks" , "chat, perhaps?" , "Creature - time in prison" , "Avian" , "that flies" .)

I've seen this clue in the Sydney Morning Herald.

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