(Sanskrit यन्त्र) Literally, "machine, instrument, engine, motor, implement, fetter, implement for holding, mystical diagram supposed to possess occult powers, trace, prop, appliance, band, apparatus, surgical instrument, any instrument for holding or restraining or fastening, restraint, tie, device, any instrument or apparatus, support, force, mechanical contrivance, barrier, means, amulet, rein."
1. Hinduism. Yantra is generally used to referred to a mystical diagram like a mandala, utilized for meditation.
2. Buddhism. (Tibetan: trulkhor, which also means "movement of body") Particular exercises taught by Padmasambhava to harness prana (energy) and acheive profound relaxation in preparation for meditation. Samael Aun Weor taught a form of Yantra as well: Sacred Rites for Rejuvenation.