Deeside bird? (3)
I believe the answer is:
jay
'bird?' is the definition.
(jay is a kind of bird)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for jay that I've seen before include "Colourful type of crow" , "-- Gatsby, F. Scott Fitzgerald character" , "Garden bird" , "Colourful British bird" , "Bird of the crow family with blue plumage" .)