A tractor-trailer or big rig, consisting of a semi-trailer and a semitruck pulling it; in American English referred to as semi-trailer truck or 18-wheeler.
A small, one-wheeled (or rarely, two-wheeled) cart with handles at one end for transporting small loads.
To convey in a wheelbarrow.
To cause the weight of an aeroplane to become concentrated around the nosewheel.