Definitions for half-track
Random House Webster's College Dictionary
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 esp. on military vehicles.
a motor vehicle with rear driving wheels on caterpillar treads.
Mil. an armored vehicle equipped with half-tracks.
Origin of half-track:
a motor vehicle propelled by half tracks; frequently used by the military
a track that goes around only rear wheels
having caterpillar treads on the rear and wheels in front
"half-track armored vehicles"
A vehicle combining both wheels and treads (caterpillar tracks).
Describing such a vehicle; half-tracked