(Sanskrit: Loom), any of numerous texts dealing with the esoteric practices of some Hindu, Buddhist, and Jaina sects. In the orthodox classification of Hindu religious literature, Tantra refers to a class of post-Vedic Sanskrit treatises similar to the Purāṇas (medieval encyclopaedic collections of myths, legends, and other topics). In this usage Tantras are, theoretically, considered to treat of theology, yoga, construction of temples and images, and religious practices; in reality, they tend to deal with such aspects of popular Hinduism as spells, rituals, and symbols. They are distinguished along Hindu sectarian lines between the Śaiva Āgamas, the Vaiṣṇava Saṃhitās, and the Śākta Tantras.

The lists of the Śākta Tantras differ considerably from one another but suggest that the earliest manuscripts date from about the 7th century. They emphasize the goddess Śakti (Shakti) as the female personification of the creative power or energy of the god. This view taken to its extreme holds that Śiva (Shiva) without his Śakti is like a corpse. In the Tantras that deal with yoga, Śakti is identified with the kuṇḍalinī, or the energy that lies coiled at the base of the spine until brought up through the body by yogic disciplines. The Tantras also stress the efficacy of yantras and maṇḍalas (ritual diagrams) and of mantras (mystic syllables or sacred formulas). Among the major Śākta Tantras are the Kulārṇava, which treats of “left-hand” practices, such as ritual copulation; the Kulacūḍāmaṇi, which discusses ritual; and the Śaradātilaka, which deals almost exclusively with magic.

The Buddhist Tantras are traced to the 7th century or earlier, the Tathāgataguhyaka being an early and extreme work. They were translated into Tibetan and Chinese from about the 9th century onward, and some texts have been preserved only in those languages, the Sanskrit originals having been lost. Among the Buddhist Tantras an important text is the Kālacakra-tantra.