caster
n. countable C1 Advanced US //ˈkæstɝ// UK //kˈɑːstɐ// cast·er
n. a small wheel attached to the bottom of furniture or machines so you can move them easily. You usually find them on office chairs and heavy tables.
n. a small, swivelling wheel mounted on a bracket and attached to the base of a heavy object to facilitate multidirectional movement.
One caster on my office chair is stuck.
The heavy industrial workbench is mounted on locking casters so it can be moved around the workshop safely.
The grand piano was fitted with brass casters to allow for precise positioning on the stage without damaging the polished hardwood flooring.
Usage
Often used in the plural when referring to the set of wheels on a single piece of furniture.