You searched for: “caster
caster, castor, castor oil
caster (KAS tuhr) (noun)
1. A small wheel on a swivel, attached under a piece of furniture or other heavy object to make it easier to move: It's a good thing that the sofa had a caster on each of its six legs because it was much easier to move it across the room.
2. Someone who throws something: Byron was a professional caster of nets in the ocean so he could catch fish.
castor (KAS tuhr) (noun)
1. The British spelling of "caster" or a swiveling roller fastened under an article of furniture or portable machines to make them movable: A castor on certain segments of furniture facilitate the movement of such structures.
2. An oily odorous secretion of beavers; used in medicine and perfumery: Salvador was surprised to learn that his wife's perfume was made from the unpleasant smelling castor of beavers.
castor oil (KAS tuhr OIL) (noun)
A viscous fixed oil, colorless or pale yellow, extracted from the seeds of the castor-oil plant which is used as a cathartic and lubrication; and also, used in paint and varnish as well as medically: When some people have bowel problems they might take castor oil as a cathartic which causes the emptying of the bowels.

The large cask of castor oil was sitting on the pallet which had casters under it for ease of movement.

It was clearly marked: CASTOR OIL so it wouldn't be confused with the small cask of beaver castor imported from Canada.