Stop in Carshalton (4)
I believe the answer is:
halt
'stop' is the definition.
(halt can mean to stop)
'in carshalton' is the wordplay.
'in' indicates the answer is hidden within the clue.
'HALT' can be found hidden inside 'carshalton'.
(Other definitions for halt that I've seen before include "Pull up" , "game" , "Small railway station" , "Falter - stop" , "Stop or pause" .)