Caster

n. shaker (i.e. pepper, salt, etc.); small wheel (on furniture)

This article is about the type of wheel. For the fictional weapon called a "caster," see Spellgun. For caster sugar see sugar.For other uses of castor, see castor.See also: Caster (Fate Stay Night), an anime characterA caster (or castor) is a type of wheel mounted with an offset steering pivot such that the wheel will automatically swivel to align itself to the direction from which it is pushed. They are commonly found on shopping carts and rolling chairs.
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Castor, n Latin name: Ricinum communis; part used: leaves, oil, roots, seeds; uses: birth control, laxative, emetic, stomach antiinflammatory, [more]Caster - Community and Resources

Noun
1. a worker who casts molten metal into finished products
(hypernym) worker
(derivation) cast, mold, mould
2. a shaker with a perforated top for sprinkling powdered sugar
(synonym) castor
(hypernym) shaker
3. a pivoting roller attached to the bottom of furniture or trucks or portable machines to make them movable
(synonym) castor
(hypernym) roller

(n.)
One who casts; as, caster of stones, etc. ; a caster of cannon; a caster of accounts.
  

(n.)
A vial, cruet, or other small vessel, used to contain condiments at the table; as, a set of casters.
  

(n.)
A stand to hold a set of cruets.
  

(n.)
A small wheel on a swivel, on which furniture is supported and moved.