half-track

noun

1. a caterpillar tread that runs over and under the rear or driving wheels of a vehicle but is not connected with the forward wheels: used especially on military vehicles.
2. a motor vehicle with rear driving wheels on caterpillar treads.
3. Military. an armored vehicle equipped with half-tracks.

noun

1. a vehicle with caterpillar tracks on the wheels that supply motive power only

n.

also halftrack, type of military vehicle, 1927, from half + track (n.).