Siddhi
Siddhi is produced by sâdhana. The former term, which literally means ” success, ” includes accomplishment, achievement, success, and fruition of all kinds.
A person may thus gain siddhi in speech, siddhi in mantra, etc. A person is siddhi also who has perfected his spiritual development. The various powers attainable—namely, anima, mahima, garima, prapti, prakamya, isitva, vasitva—the powers of becoming small, great, light, heavy, attaining what one wills, and the like—are known as the eight siddhis.
The thirty-ninth chapter of the Brahmavaivarta Purana mentions eighteen kinds, but there are many others including such minor accomplishments as nakhadarpanasiddhi or “nail-gazing.” The great siddhi is spiritual perfection. Even the mighty powers of the “eight siddhis ” are known as the ” lesser siddhi, ” since the greatest of all siddhis is full liberation (mahanirvana) from the bonds of phenomenal life and union with the Paramatma, which is the supreme object (paramartha) to be attained through human birth.