Drove police off (6)
I believe the answer is:
rancid
'off' is the definition.
(thesaurus)
'drove police' is the wordplay.
'drove' becomes 'ran' ('run' can be a synonym of 'drive').
'police' becomes 'cid'.
'ran'+'cid'='RANCID'
(Other definitions for rancid that I've seen before include "Smelly and going bad" , "Smelling or tasting of stale fat" , "Stale, rank" , "Rank-smelling." , "Sour like stale fat" .)