horsebox

noun3

1. •
   (UK) A motor vehicle for transporting horses.
2. •
   A container for transporting horses in, whether by road, rail, or sea.
3. •
   (UK, no longer used) A van-type railway vehicle specially built for the carriage of horses.

   • On October 31 [...] Laira "Grange" No. 6871 passed through Wolverhampton with a Holyhead-Didcot horsebox special. — 1960