Definition of "magic circle" []

• A circle marked by a practioner of magic, used as magical protection or to form a magical area. (noun)
• An 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. (noun)

Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License

• "The young Lord Pervil, the star of the present day, was now drawn into the magic circle of Camilla; this was full sufficient to bring into it every minor luminary of his constellation; and even the resplendent and incomparable beauty of Indiana, even the soft and melting influence of the expressively lovely Mrs. Berlinton, gave way to the superior ascendance of that varied grace, and winning vivacity, which seemed instinctively sharing with the beholders its own pleasure and animation."
• "Having arrived at the spot, the magician first of all traces the magic circle within which, we are told, no evil spirit can enter; he then commences the magic rite, involving various prayers and conjurations, a medley of meaningless words, and, in the case of the black art, a sacrifice."