(Sanskrit nastika, it doesn't exist)
In Hinduism the schools of religious thought are categorized as either:
(1) Astika — which accept the authority of the Vedas, e.g. Nyaya, Vaisesika, Samkhya, Yoga, Mimamsa, and Vedanta.
(2) Nastika — which reject the authority of the Vedas, e.g. Carvaka, Ajivika, Jainism, and Buddhism.
1. In Sanskrit Astika means "it exists" and Nastika means "it doesn't exist."