The word Tantra is of obscure origin. For which a number of derivations have been suggested, among them: the word tan, 'stretch', or that which extends the faculties of man; tanu, 'body', because of its stress on the bodily functions; tanti, 'rope', for securing the devotee; tantri, 'harp', for the music and beauty of its philosophy; tadantara, `interiorners', from its secret teachings; tantu, 'thread', suggesting the 'loom' of the Tantras whereon is revealed the warp and woof (male and female principles) of which the vast magical fabric of the cosmos is composed.
Chief among the extreme left-hand tantrik cults are those grouped under the heading cults are those grouped under the heading of kaula, whose votaries are known as kaulika. The term is of undetermined origin, variously held to be derived from. The name of the goddess Kali; the kaulina, 'nobility', as its heroes (vira) are called; the kula or family of the chosen; the kaulika or weaver on the tantra or loom of the sectarian beliefs; the goddess kaulini, associated with the kundalini and its arousal; the followers of the kaulo panishad, further amplified in the kularnava and other tantras.
The cannon of tantrism, called the Tantra, is believed by the tantrika (follower of tantrism) to have been revealed by Shiva as the specific scriptures and is regarded by the adherent as superior to the Vedas.
An important feature in tantrism is the element of the direful and the awe-inspiring, to which the term bhairav, 'terror' is applied. Its source is Shiva in his aspect of Bhairava and his consort shakti in her aspect of Bhairavi (kali, Durga, Chandi etc.) who bodyforth the elements of universal dread.
The scriptures of this shakti worship are the Tantras, literature frequently of the grossest description — since the special forms of the energy thus worshipped are displayed I magical powers. Indeed the five requisities for Tantra worship are the five namely Madya, Mamsa, Matsya, Mudra and Maithuna. Moreover, the Tantras are divided into right handed and left handed Tantras. Each goddess has a double nature, one gentle and the other fierce. It needs hardly to be said that in the practices of the vamacharis, or "left-handed tantric worshippers," we reach the lowest depths of the degradation of Indian idolatry.