Drop rent (4)
I believe the answer is:
tear
I believe this clue is a double definition.
'drop' is the first definition.
(teardrop)
'rent' is the second definition.
(I know that rent can be written as tear)
(Other definitions for tear that I've seen before include "Rent - drop" , "A drop of optical moisture" , "Dash; drop" , "charge" , "Rip, sever roughly" .)