an evil spirit or devil, especially one thought to possess a person or act as a tormentor in hell

he was possessed by an evil demon

each of the damned souls was guarded by a group of hideous demons

a forceful or skilful performer of a specified activity

a friend of mine is a demon cook

a police officer, especially a detective

a couple of demons interrogated him about a job that had been pulled the night before

a background process that handles requests for services such as print spooling and file transfers, and is dormant when not required

(in ancient Greek belief) a divinity or supernatural being of a nature between gods and humans