Another name for the Carvaka school, a materialistic and atheistic Nastika school that originated in India around 6th century BCE.
They were strict empiricists, e.g. they only accepted sense data as valid information; in fact, they considered other forms of information gathering such as testimomy, analogy, and inference as unreliable.
Consistent with this epistomology, they also rejected the existence of Brahman and Atman, and the other mystical phenomena found in the Vedas, making them, as far as we know, history's first true atheists.
Having arrived at a similar philosophical destination as the Epicureans (i.e. the life as we perceive it is all we know and probably all we will ever have), they promoted the goal of eliminating pain and enjoying the here and now.
Sadly, but not suprisingly, all of the original Lokayata texts are lost. We only know about them through the writings of their opponents.