Tertön (T. gter ton གཏེར་སྟོན་) is a Tibetan Buddhist term for a "treasure revealer" or "treasure-finder."
A terton is a highly-realized master that reveals hidden teachings and presents them at a spiritually efficacious time. In particular, this term is used widely in the Nyingma tradition, where it refers to individuals who, in a previous life, were students of the master Padmasambhava. According to the Nyingma tradition, Padmasambhava and his consort Yeshe Tsogyal hid many teachings around Tibet that they foresaw would be beneficial to beings at a later time. The reincarnations of his students are able to find these hidden teachings, called "treasures" (T. terma), and reveal them to beings in the age when they are needed.
- Terton, Rangjung Yeshe Wiki