castor
(also caster), / ˈkɑ:stə(r); ?@ ˈkæs-; `kæstɚ/ n
1 any of the small swivelling wheels fixed to the bottom of a piece of furniture so that it can be moved easily （家具的）小脚轮. =>illus at App 1 见附录1之插图, page xvi.
2 small container with holes in the top for sprinkling sugar, etc 调味瓶（顶端有小孔, 用以撒糖等）.