late 14c., "tutelary or moral spirit" who guides and governs an individual through life, from Latin genius "guardian deity or spirit which watches over each person from birth; spirit, incarnation; wit, talent;" also "prophetic skill," originally "generative power" (or "inborn nature"), from PIE *gen(e)-yo-, from root *gene- "to produce, give birth, beget" (see genus). Sense of "characteristic disposition" of a person is from 1580s. Meaning "person of natural intelligence or talent" and that of "exalted natural mental ability" are first recorded 1640s.