genius

The word 'genius' entered English in the late 14th century from Latin, where 'genius' originally referred to a tutelary or attendant spirit allotted to every person at birth. This Latin term is believed to derive from the Proto-Indo-European root 'gen-', meaning "to give birth, beget," which is also the source of words like 'generate' and 'genus'. The logic of its evolution is clear: from a spirit presiding over one's birth and destiny, the meaning broadened to signify the innate, guiding spirit or character of a person or place. By the 17th century, this sense of an inborn guiding spirit or natural inclination developed into the modern abstract meaning of extraordinary innate intellectual or creative power, and later, a person possessing such power.

The entire word 'genius' is a simplex loanword from Latin. It does not neatly segment into smaller, meaningful substrings in modern English spelling that correspond to distinct morphemes (e.g., 'geni' + 'us' would be misleading as 'geni' is not a standalone morpheme in English).