genius (n.)
late 14c., "tutelary god (classical or pagan)," from Latin genius "guardian deity or spirit which watches over each person from birth; spirit, incarnation, wit, talent;" also "prophetic skill," originally "generative power," from root of gignere "beget, produce" (see kin), from PIE root *gen- "produce." Sense of "characteristic disposition" is from 1580s. Meaning "person of natural intelligence or talent" and that of "natural ability" are first recorded 1640s.