Definition of casters:
(n) :
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).
(n) :
A shaker with a perforated top for sprinkling condiments such as sugar, salt, pepper, etc.
(n) :
Someone or something that casts.
(n) :
A stand to hold a set of shakers or cruets.
(n) :
(automotive) 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.
(v) :
To act as a caster