The uncreated and deathless Buddhic element or principle concealed within all sentient beings to achieve Awakening; the innate (latent) Buddha essence (esp. in the Tathagatagarbha sutras, Tendai/Tiantai, Nichiren thought).
Buddha-nature or Buddha Principle refers to several related terms, most notably Tathāgatagarbha and Buddhadhātu. Tathāgatagarbha means "the womb" or "embryo" (garbha) of the "thus-gone" (tathagata), or "containing a tathagata", while Buddhadhātu literally means "Buddha-realm" or "Buddha-substrate".