Train carriage (5)
I believe the answer is:
coach
This clue is a double definition.
'train' is the first definition.
(I know that train can be written as coach)
'carriage' is the second definition.
(I know that coach is a type of carriage)
(Other definitions for coach that I've seen before include "Stage" , "Bus-like vehicle" , "Trainer and train carriage" , "Train - or part of one!" , "Instruct" .)