One who, or that which, bolsters.
A person or thing that is seminal and influential.
The front part of a semi-trailer type truck, i.e., the tractor to which the trailer part attaches.
A military or heavy construction vehicle.
The initial agent that is the cause of all things.
A machine, such as a water wheel or steam engine, that receives and modifies energy as supplied by some natural source or fuel and transforms it into mechanical work