Satan is an example of a demon.
An evil murderer is an example of a demon.
A great video game player who is very enthusiastic is an example of a video game demon.
The demon of jealousy.
The demon of drug addiction.
Worked away like a demon; a real demon at math.
The demon drink.
Origin of demon
- Middle English from Late Latin daemōn from Latin spirit from Greek daimōn divine power dā- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition