castor
n. countable C1 Advanced US //ˈkæstɝ// UK //kˈɑːstɐ// cas·tor
n. a small wheel fixed to the bottom of a piece of furniture. It allows you to move heavy things like chairs or tables easily across the floor.
n. a small, swivelling wheel attached to the base of furniture or heavy equipment to facilitate multidirectional movement.
One castor on my office chair is broken.
The heavy dining table is fitted with castors so it can be moved aside for cleaning.
Industrial-strength castors are essential for stage equipment, as they must support significant weight while allowing for silent and fluid transitions during a live performance.
From Ancient Greek Κάστωρ (Kástōr), from Ancient Greek κάστωρ (kástōr, “beaver”).
Usage
Commonly spelled 'caster' in American English; 'castor' is the standard British spelling.