Big-eyed baby bird (5)
I believe the answer is:
owlet
'big-eyed baby bird' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for owlet that I've seen before include "Small bird of prey from Africa and Asia" , "Junior member of parliament" , "Wise young" , "Little nocturnal bird" , "Little hooter?" .)