The Sanskrit word Siddhi is the shining manifestation of success emanating from the Cosmic Spirit. In mundane terms the word relates to the idea of accomplishment, perfection or occult power. Inside the International Nath Order, Siddhi is described as an important attainment and focus for all serious Nath aspirants. It is the spiritual well spring which grants the four goals of human life: artha, kama, dharma and moksha.
In Indian mythology, Siddhi is one of the two spouses of the elephant headed divinity, Ganesha.
Magick and Mystick by Sri Kapilnath