1. (n.) A ring; a ringlike part or space.

2. (n.) A space contained between the circumferences of two circles, one within the other.

3. (n.) The solid formed by a circle revolving around a line which is the plane of the circle but does not cut it.

4. (n.) Ring-shaped structures or markings, found in, or upon, various animals.

O annular muscle annulus aureole chaplet circle circuit circumference circus closed circle corona coronet crown cycle diadem discus disk eternal return fairy ring garland glory halo lasso logical circle loop looplet magic circle noose orbit radius ring rondelle round roundel saucer sphincter vicious circle wheel wreath