Dictionary

Someone possessing extraordinary intelligence or skill; especially somebody who has demonstrated this by a creative or original work in science, music, art etc.

Example: I think that would qualify as not smart, but genius... and a very stable genius at that!

Extraordinary mental capacity.

Inspiration, a mental leap, an extraordinary creative process.

Example: a work of genius.

The tutelary deity or spirit of a place or person.

Ingenious, brilliant, very clever, or original.

Example: What a genius idea!