Eyelash make-up (7)
I believe the answer is:
mascara
'eyelash make-up' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for mascara that I've seen before include "that accentuates lashes" , "Makeup used to darken and thicken the eye lashes" , "Type of make-up" , "Make-up for eyelashes" , "black application" .)