Pioneer's vehicle (5)
I believe the answer is:
wagon
'pioneer's vehicle' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wagon that I've seen before include "Vehicle (on which abstainers travel?)" , "Four-wheeled goods vehicle" , "Freight truck" , "On this, one keeps dry!" , "Trailer, railway truck" .)