Army vehicle (8,3)
There are a few possibilities for this:
armoured car
'army vehicle' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for tank that I've seen before include "Car fuel container" , "Cistern - armoured vehicle" , "Fuel store" , "Aquarium; army vehicle" , "Armoured vehicle; large container" .)
'army vehicle' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for jeep that I've seen before include "Small four-wheel drive vehicle" , "Army vehicle, 4-wheel drive" , "4WD vehicle" , "Military four-wheel-drive vehicle" , "Sturdy vehicle" .)
(Other definitions for armoured car that I've seen before include "Heavily-protected vehicle" , "Military vehicle" , "Reinforced vehicle" .)