Mahāmudrā (Sanskrit, Tibetan: Chagchen, Wylie: phyag chen, contraction of Chagya Chenpo, Wylie: phyag rgya chen po) literally means "great seal" or "great symbol." It "is a multivalent term of great importance in later Indian Buddhism and Tibetan Buddhism" which "also occurs occasionally in Hindu and East Asian Buddhist esotericism."
The name refers to a body of teachings representing the culmination of all the practices of the Sarma schools of Tibetan Buddhism, who believe it to be the quintessential message of all of their sacred texts. The mudra portion denotes that in an adept's experience of reality, each phenomenon appears vividly, and the maha portion refers to the fact that it is beyond concept, imagination, and projection.
The usage and meaning of the term mahāmudrā evolved over the course of hundreds of years of Indian and Tibetan history, and as a result, the term may refer variously to "a ritual hand-gesture, one of a sequence of 'seals' in Tantric practice, the nature of reality as emptiness, a meditation procedure focusing on the nature of Mind, an innate blissful gnosis cognizing emptiness nondually, or the supreme attainment of buddhahood at the culmination of the Tantric path."
According to Jamgon Kongtrul, the Indian theoretical sources of the mahāmudrā tradition are Yogacara Tathagatagarbha (Buddha-nature) texts such as the Samdhinirmocana sutra and the Uttaratantra. The actual practice and lineage of mahāmudrā can be traced back to wandering mahasiddhas or great adepts during the Indian Pala Dynasty (760-1142), beginning with the 8th century siddha Saraha. Saraha's Dohas (songs or poems) are the earliest mahamudra literature extant, and promote some of the unique features of mahamudra such as the importance of Pointing-out instruction by a guru, the non-dual nature of mind, and the negation of conventional means of achieving enlightenment such as samatha-vipasyana meditation, monasticism, rituals, tantric practices and doctrinal study in favor of mahamudra 'non-meditation' and 'non-action'. Later Indian masters such as Padmavajra, Tilopa, and Gampopa incorporated mahamudra into tantric, monastic and traditional meditative frameworks.