Stop providing support (4)
I believe the answer is:
stem
This clue is a double definition.
'stop' is the first definition.
(stemming is a kind of stopping)
'support' is the second definition.
(I've seen this before)
'providing' is the link.
(Other definitions for stem that I've seen before include "Upward part of a plant" , "Originate (from)" , "Check - part of a plant" , "Staunch (flow)" , "Dam" .)