esoteric Buddhism

A general term for certain Buddhist schools and practices originally developing in parallel with Hindu (see Hinduism) tantra with mutual influence at a later stage. It is distinguished from exoteric Buddhism by its secrecy; rather than being given openly these teachings are available only to students who have received a proper initiation (abhiṣeka) from a guru who stands in a valid lineage of masters and disciples. Practice will then make use of a number of techniques in which the student visualizes a guardian Buddha, Bodhisattva, or deity with whom he or she has a special relationship established at their initiation, and then realizes his or her non-duality with that being. This appropriation of the divine guardian's role involves the establishment and spiritual fortification of a special place of practice and the use of ritual formulae (mantras), gestures (mudrās), and visualization techniques. Occasionally, this also makes use of sexual imagery or actual ritualized sexual practices as a way of harnessing the physical energy and the feeling that one has transcended personal boundaries and merged with another that come with orgasm. Esoteric Buddhist schools, including many Tibetan lineages, Chen-yen in China, and Shingon and Tendai in Japan, claim that these techniques represent a short-cut to enlightenment and enable one to attain Buddhahood in this lifetime. Many of the techniques are also used for other this-worldly purposes such as weather control and healing.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)