cakraratana (Sanskrit; Pāli, cakkaratana). The ‘wheel treasure’ of a cakravartin or universal ruler. This treasure is a fabulous wheel having a thousand spokes and bedecked with jewels that appears when a cakravartin is born and disappears when he dies. A magical device, it carries the cakravartin and his retinue to each of the four continents where he is received as the rightful ruler, before returning to his palace where it remains as an ornament. Eventually the wheel begins to slip from its position, announcing the end of the king's reign.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)