Companion, a type causing hilarity in horse-drawn vehicle (7)
I believe the answer is:
chariot
'horse-drawn vehicle' is the definition.
(I've seen this before)
'companion a type' is the wordplay.
'companion' becomes 'cha' (I've seen this in other clues).
'a type' becomes 'riot' (I am not sure about this - if you are sure you should believe this answer much more).
'cha'+'riot'='CHARIOT'
'causing hilarity in' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for chariot that I've seen before include "A torch I placed on old wheeled two-vehicle" , "Ancient horse-drawn war vehicle" , "Roman two-wheeled vehicle" , "Two-wheeled carriage of ancient times, as used by Ben Hur" , "Two-wheeled horse-drawn vehicle in ancient Rome" .)