Ride south with Peg (4)
I believe the answer is:
spin
'ride' is the definition.
(thesaurus)
'south with peg' is the wordplay.
'south' becomes 's' ('S' can be a synonym of 'south').
'with' says to put letters next to each other.
'peg' becomes 'pin' ('pin' can be a synonym of 'peg'**).
's'+'pin'='SPIN'
(Other definitions for spin that I've seen before include "Political bias" , "Give it a whirl" , "Rotate quickly" , "Rotate; ride" , "Rotate like toy top" .)