RIP in Split (4)
I believe the answer is:
tear
I believe this is a double definition.
'rip' is the first definition.
(I know that rip can be written as tear)
'split' is the second definition.
(I know that split can be written as tear)
'in' is the link.
(Other definitions for tear that I've seen before include "Rip, pull apart" , "A rip and a sign of sadness" , "Drop secreted by the lacrimal glands" , "Droplet; rip" , "Come apart" .)