Ancient horse-drawn vehicle (7)
I believe the answer is:
chariot
'ancient horse-drawn vehicle' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for chariot that I've seen before include "Roman two-wheeled vehicle" , "ceremonial carriage" , "Ben Hur transport?" , "A torch I placed on old wheeled two-vehicle" , "Old vehicle (of fire?)" .)