From Latin 'genius' (guardian spirit), from PIE *ǵenh₁- — originally a personal spirit in Roman religion, not a human quality.
Exceptional intellectual or creative power or other natural ability; a person who possesses such ability.
From Latin 'genius' (attendant spirit, innate nature, talent, wit), from 'gignere' (to beget, to produce, to bring forth), from PIE *ǵenh₁- (to beget, to give birth, to produce). In Roman religion, a 'genius' was a divine spirit born with each person — a personal guardian deity that embodied one's innate productive power. When we call someone 'a genius,' we are unknowingly invoking the Roman belief that exceptional ability