King's vehicle reversing in the other direction (4)
I believe the answer is:
back
'in the other direction' is the definition.
(going back)
'king's vehicle reversing' is the wordplay.
'king' becomes 'K' (abbreviation for king in chess).
'vehicle' becomes 'cab' (cab is a kind of vehicle).
'reversing' is a reversal indicator.
'k'+'cab'='kcab'
'kcab' in reverse letter order is 'BACK'.
(Other definitions for back that I've seen before include "Support - football player" , "Returned" , "Golf holes 10-18" , "See 17" , "Second" .)