Sir Bedivere's bird (5)
I believe the answer is:
diver
'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 not sure how the hidden word 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" .)