In the Samkhya system, one of the three universal constituents (Skt. guṇa) that are components of primal matter (Skt. pradhāna) or natural matter (Skt. prakṛti) and not qualities distinct from it. In different contexts, it refers to luminosity, lightness, strength and pleasure.
Tibetan: སྙིང་སྟོབས། snying-stobs
J. Hopkins: Power of heart, lightness