Definitions
1.NounA circle marked on the ground by a practitioner of magic, used as magical protection or to form a magical area.
2.NounIn traditional cultures, a circle drawn on the ground marking out a sacred, protected, or ritually charged space.
3.NounAn arrangement of natural numbers on circles such that the sum of the numbers on each circle and the sum of numbers on diameter are identical.
4.NounThe imagined space, separate from the real world, in which players in a virtual reality system experience immersion.