Hair on an eyelid (4)
I believe the answer is:
lash
'hair on an eyelid' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lash that I've seen before include "Stroke of the whip" , "Fasten with rope; whip" , "Whip; securely fasten" , "Beat severely with a whip" , "Hit with a whip" .)