caster

Short definition from Wiktionary

Noun

1. 1
   Someone or something that casts.
2. 2
   A wheeled assembly attached to a larger object at its base to facilitate rolling. A caster usually consists of a wheel (which may be plastic, a hard elastomer, or metal), an axle, a mounting provision (usually a stem, flange, or plate), and sometimes a swivel (which allows the caster to rotate for steering).
3. 3
   A shaker with a perforated top for sprinkling condiments such as sugar, salt, pepper, etc.
4. 4
   A stand to hold a set of shakers or cruets.
5. 5
   The angle of the axis around which a car's front wheels rotate when the steering wheel is turned, with a vertical axis being defined as zero caster.

Verb

1. 1
   To act as a caster

Proper noun

1. 1
   A surname.