genius (n.) Look up genius at Dictionary.com
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; the male spirit of a gens," originally "generative power" (or "inborn nature"), from PIE *gen(e)-yo-, from root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups. 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.