Bird bites when upset -- not good (4)

I believe the answer is:

swan

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'bird' is the definition.
(swan is a kind of bird)

I don't understand how the rest of the clue works.

(Other definitions for swan that I've seen before include "Large, long-necked bird" , "Shakespeare is called The .... of Avon" , "possibly mute" , "Stately aquatic bird" , "Sweet name 8 [OF SHAKESPEARE]" .)

I've seen this clue in The Telegraph.

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