Tantra (Sanskrit: तन्त्र , Oriya: ତନ୍ତ୍ର”loom, warp”; hence “principle, system, doctrine”, from the two root words tanoti “stretch, extend”, and trayati “liberation”), anglicised tantricism or tantrism or tantram, refers to esoteric schools of Hinduism and Buddhism and to the scriptures (called “Tantras”) commonly identified with the worship of Shakti. Tantra deals primarily with spiritual practices and ritual forms of worship that aim at liberation from ignorance and rebirth, the universe being regarded as the divine play of Shakti and Shiva. In “left-handed” Tantra (Vamachara), ritual sexual intercourse is employed as a way of entering into the underlying processes and structure of the universe.
Tantrism originated in the early centuries CE and developed into a fully articulated tradition by the end of the Gupta period. It has influenced the Hindu, Sikh, Bön, Buddhist, and Jain religious traditions and spread with Buddhism to East Asia and Southeast Asia.
Definition courtesy Wikipedia.