Sanātana-Dharma Skt., from sanātana: “imperishable, eternal”; the eternal religion or truth of Hinduism. Hindus use this name to characterize their religion because it does not derive from a human founder; rather, the truth was revealed to the rishis. The scriptures (shruti) are based on these revelations.
Source: The Encyclopedia of Eastern Philosophy and Religion: Buddhism, Hinduism, Taoism, Zen. Shambhala Publications, Inc.
External link: Sanātana Dharma