An intellectually brilliant person who excells at using his or her mental abilities for negative or harmful ends; especially a criminal mastermind .
The spirit each person is believed to have in attendance, according to certain religious or mythological traditions, which tries to negatively influence him, and is opposed by his good genius; loosely, someone who is a bad influence.
An intelligent, self-aware being.
Attempting to appear wise or discerning.
Of a species or life-form, possessing intelligence or self-awareness.