Government vehicle crushed by Mark's vehicle (7)
I believe the answer is:
dogcart
'vehicle' is the definition.
(dogcart is a kind of vehicle)
'government vehicle crushed by mark's' is the wordplay.
'government' becomes 'g' (abbreviation for government).
'vehicle' becomes 'car' (car is a kind of vehicle).
'crushed by' means one lot of letters goes inside another.
'mark' becomes 'dot' (dotting is a kind of marking).
'g'+'car'='gcar'
'gcar' put within 'dot' is 'DOGCART'.
(Other definitions for dogcart that I've seen before include "Two-wheeled vehicle" , "Light (actually horse-drawn) vehicle" .)