Terma (Tib. gter ma). Spiritual treasures hidden by Guru Rinpoche and Yeshe Tsogyal in the earth and in the minds of disciples to be revealed at the appropriate time by ‘treasure revealers’ or tertöns.
“In order to prevent the deep teachings and sacred objects of tantra from becoming mixed, diluted, or lost in the distant future, and in order to maintain their blessing powers afresh for future followers, Guru Rinpoche and Yeshe Tsogyal concealed them. They are discovered at the appropriate time by realized masters through their enlightened power.”
--From Masters of Meditation and Miracles, by Tulku Thondup Rinpoche.