Mascara ruiner, maybe (4)
I believe the answer is:
tear
'mascara ruiner maybe' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tear that I've seen before include "Rip - drop from eye" , "'A rip, binge or drop of saline solution (4)'" , "Split - career" , "Dash; drop" , "Drop secreted by the lacrimal glands" .)