Siddhi means accomplishment. It names the powers attributed to advanced yogins, such as knowing others’ minds or becoming very small, which the Yoga Sūtras describe and warn against as obstacles. In tantric traditions siddhi also means the supreme attainment, liberation, and a siddha is a perfected one.
Siddhi
An extraordinary power or accomplishment attained through yoga, and also perfection or liberation itself.
Also: Siddhi, siddhis