Behind a street, the camper van ends (6)
I believe the answer is:
astern
'behind' is the definition.
(I've seen this before)
'a street the camper van ends' is the wordplay.
'street' becomes 'st'.
'ends' says to take the final letters.
The last letters of 'the camper van' are 'ern'.
'a'+'st'+'ern'='ASTERN'
(Other definitions for astern that I've seen before include "Behind (a boat)" , "Towards the back (of a ship)" , "Behind the back of a ship" , "Abaft" , "at the vessel's rear" .)