Visit to postpone (4)
I believe the answer is:
stay
I believe this clue is a double definition.
'visit' is the first definition.
(I've seen this before)
'to postpone' is the second definition.
(I've seen this before)
(Other definitions for stay that I've seen before include "Put off - visit" , "control" , "Remain; steady" , "Support, delay" , "Remain; prop" .)