Crotchety one (4)
I believe the answer is:
coot
'crotchety one' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for coot that I've seen before include "Blackish aquatic bird" , "Slow-flying birds, duck-like" , "'Bald' water bird" , "Supposedly bald bird" , "Water bird of rail family" .)