Split career (4)
I believe the answer is:
tear
This clue is a double definition.
'split' is the first definition.
('tear' can be a synonym of 'split')
'career' is the second definition.
(thesaurus)
(Other definitions for tear that I've seen before include "Secretion of the lachrymal glands" , "Dash; drop" , "Shred" , "Optical sign of sorrow" , "Small flaw, as in glass" .)