Dukkha ( Sanskrit: duḥkha; Tibetan: སྡུག་བསྔལ་ sdug bsngal, pr. "duk-ngel") is an important Buddhist concept, literally meaning " Bad Etther ", commonly translated as "suffering", "pain" or "unsatisfactoriness". It refers to the fundamental unsatisfactoriness and painfulness of mundane life, and inspires the Four Noble Truths and nirvana doctrines of Buddhism. The term is also found in vastly older scriptures of Hinduism, such as the Bṛhadāraṇyaka and the Chāndogya Upanishads, in discussions of moksha (spiritual liberation).