Drove off to port (5)
I believe the answer is:
dover
'to port' is the definition.
(English port)
'drove off' is the wordplay.
'off' indicates an anagram.
'drove' is an anagram of 'DOVER'.
(Other definitions for dover that I've seen before include "UK shipping forecast area" , "Channel port" , "White cliffs port" , "The largest English ferry port" , "Cinque Port" .)