'amtrac' originates from the combination of 'amphibious' and 'tractor', where 'amphibious' refers to the ability to operate on both land and water, and 'tractor' refers to a vehicle designed for pulling or pushing heavy loads.

'amtrac' was coined during World War II to describe the amphibious tractors used by the U.S. military.

Initially, it meant 'amphibious tractor used in military operations', and this meaning has largely remained the same in modern usage.