loose box
noun1
UK A separate compartment of a building in which livestock are free to move about; especially a form of stable for horses.
- Long before you see the lean, handsome heads peering mildly over the half-doors of the loose boxes, you know that East Ilsley's business is training racehorses.1980, AA Book of British Villages, Drive Publications Ltd, page 164:
2
Archaic A brougham or other vehicle kept for the use of a dame de compagnie.