noun An evil creature, the objectification of a hostile and destructive force.
noun A man with red or orange skin and a pair of horns on his head, a pointed goatee, and a long tail, who carries a pitchfork, represents evil, and is portrayed to children as a boogeyman who punishes bad behavior.
noun The bad part of the conscience; the opposite to the angel.
The devil in me wants to let him suffer.
noun A wicked or naughty person, or one who harbors reckless, spirited energy, especially in a mischievous way; usually said of a young child.
Those two kids are devils in a toy store.
noun A thing that is awkward or difficult to understand or do.
That math problem was a devil.
noun Hell.
What in the devil is that?
noun A person, especially a man; used to express a particular opinion of him, usually in the phrases poor devil and lucky devil.