Sir Bedivere's bird (5)

I believe the answer is:

diver

I'm a little stuck... Click here to teach me more about this clue!

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

'sir bedivere's' is the wordplay.
'DIVER' is hidden within the letters.
But, I'm uncertain how this is indicated.

Can you help me to learn more?

(Other definitions for diver that I've seen before include "Drive (anag.)" , "Grebe maybe" , "Frogman" , "Large waterbird" , "One plunges head first into water" .)

I've seen this clue in the Evening Standard.

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