Two-wheeled horse-drawn vehicle (7)
I believe the answer is:
chariot
'two-wheeled horse-drawn vehicle' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for chariot that I've seen before include "former military vehicle" , "Haricot (anag)" , "Two-wheeled carriage of ancient times, as used by Ben Hur" , "Two-wheeled horse-drawn vehicle used in battle" , "'Two-wheeled, horse-drawn vehicle (7)'" .)