A toroidal vortex in a fluid or gas, i.e. a region where the fluid mostly spins around an imaginary axis line that forms a closed loop.

(algebra) An integral domain D such that for every element x of its field of fractions F, at least one of x or x⁻¹ belongs to D.

plural of valuation ring

(geometry, dated) A torus.

plural of anchor ring

(historical) A Victorian love token, a ring set with precious stones whose initial letters spelled regard (e.g. ruby, emerald, garnet, amethyst, ruby, diamond) or some other word of affection.

plural of regard ring

An annular tympanic bone, to which the tympanic membrane is attached.

plural of tympanic ring

plural of rod ring