Look at a little donkey eventually (3)
I believe the answer is:
eye
'look at' is the definition.
(I've seen this in another clue)
'a little donkey eventually' is the wordplay.
'a little' indicates the answer is hidden within the clue.
'EYE' is hidden in the letters of 'donkey eventually'.
(Other definitions for eye that I've seen before include "Four [NEEDLEFUL] may pass through this" , "Ogle" , "9 across village" , "Observe narrowly" , "Light-detector" .)