cast·er 
(kăstər)
(kăstər)n.
1. One that casts: a caster of nets.
2. also cas·tor (kăstər) A small wheel on a swivel, attached under a piece of furniture or other heavy object to make it easier to move.
3. also castor
a. A small bottle, pot, or shaker for holding a condiment.
b. A stand for a set of condiment containers.