"Great blue” bird (5)
I believe the answer is:
heron
'great blue bird' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for heron that I've seen before include "Large fish-eating bird" , "Wading bird with long neck and legs" , "Tall wading bird" , "Grey or white long-legged wading bird" , "Rhone (anag) - bird" .)