A term used in Tibetan and Tantric Buddhism for someone who embodied the perfect siddhi (psychic or supernatural abilities) through their sadhana (practice) of yoga and tantra. There are about eighty-four mahasiddhas that have been referenced in hagiographies and poetic verses, and they are considered to be the founders of Vajrayana Buddhism. Scholars have suggested that these figures likely lived between c. 750–1150 CE. From the Sanskrit mahasiddha, meaning “great adept.”