Lorry (5)
(Other definitions for wagon that I've seen before include "Four-wheeled goods vehicle" , "Trailer, railway truck" , "Vehicle (on which abstainers travel?)" , "Vehicle for transporting goods" , "Railway freight vehicle" .)
'lorry' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for truck that I've seen before include "trade" , "Vehicle (with which one has no dealings?)" , "See 14" , "Exchange" , "Goods vehicle" .)
'lorry' is the definition.
(articulated lorry is a semi-trailer truck)
This is the entire clue.
(Other definitions for artic that I've seen before include "rig" , "Large truck (informal)" , "Polar region" , "Manoeuvrable lorry" , "Region around the North Pole" .)