swastika (Sanskrit, svastika). An ancient sign said to be of solar origin and signifying good luck. The sign may be Neolithic and is found world-wide. Its Indian name comes from Sanskrit ‘sv-asti’ meaning good fortune, luck, or success. The swastika is a cross with the extremities of each arm bent at right angles. It is used as an auspicious mark on images or structures, and is often found on the chest, palms, or soles of the feet of Buddhas and Jinas. It is also used in the earliest Buddhist art which does not represent the Buddha in human form.

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