1) Animal transportation vehicle 2) Conveyance 3) Transport 
The term horsebox could refer to either a motorised vehicle adapted to carry horses (more generally known as a horse van in North America or Australasia), or a trailer (known as a horse float in Australasia). Horseboxes (motorised) can vary in size, depending on the number and size of horses to be carried. In Europe, horseboxes are developed from ...
[n] - a conveyance (railroad car or trailer) for transporting racehorses
noun a conveyance (railroad car or trailer) for transporting racehorses