Come to a standstill (4)
I believe the answer is:
stop
'come to a standstill' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stop that I've seen before include "Bung" , "Come to a halt" , "Post (anag.)" , "Stay" , "Plug - organ knob - bus halt - period" .)