demon
noun
an evil spirit; devil or fiend.
demon
1 American
[dee-muhn]
/ ˈdi mən /
noun
-
demons
plural
-
an evil spirit; devil or fiend.
-
an evil passion or influence.
-
a person considered extremely wicked, evil, or cruel.
-
a person with great energy, drive, etc..
He's a demon for work.
-
a person, especially a child, who is very mischievous.
His younger son is a real little demon.
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Australian Slang. a policeman, especially a detective.
adjective
-
of, pertaining to, characteristic of, or noting a demon.
-
possessed or controlled by a demon.
demon-
2
American
demon
British
/ ˈdiːmən /
noun
-
an evil spirit or devil
-
a person, habit, obsession, etc, thought of as evil, cruel, or persistently tormenting
-
Also called: daemon. daimon. an attendant or ministering spirit; genius
the demon of inspiration
-
-
a person who is extremely skilful in, energetic at, or devoted to a given activity, esp a sport
a demon at cycling
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( as modifier )
a demon cyclist
-
-
a variant spelling of daemon
-
informal a detective or policeman
-
computing a part of a computer program, such as a help facility, that can run in the background behind the current task or application, and which will only begin to work when certain conditions are met or when it is specifically invoked
Usage
What does demon- mean? Demon- is a combining form used like a prefix meaning “demon.” It is used in a few technical terms, especially in theology. Demon- comes from the Greek daimónion, meaning “thing of divine nature” and ultimate source of the English word demon. Among Jewish and Christian writers, daimónion was used to mean “evil spirit.”Demon- is a variant of demono-, which loses its -o- when combined with words or word elements beginning with vowels. Want to know more? Read our Words That Use demono- article.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of demon
1350–1400; Middle English < Latin daemonium < Greek daimónion, thing of divine nature (in Jewish and Christian writers, evil spirit), neuter of daimónios, derivative of daímōn; demon ( def. 6 ) < Latin; see daemon
Explanation
A demon is an evil, mythical monster or spirit. Stories about demons are featured in a variety of different religious traditions. You might come across a demon in a supernatural fairy tale, or even in the Christian Bible. Demons are often interchangeable with devils, and both words are sometimes used to talk about a cruel, fiendish person. If you're extremely good at something, you also might be described as a demon: "She's a demon at bowling." The Greek root, daimon, doesn't have the same negative connotations — it means "spirit or deity."
Vocabulary lists containing demon
The House of Hades
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"Making Faces"
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Durango’s Quinn Simmons continues to race like a mustached demon, and it’s a little baffling his Lidl-Trek team isn’t more committed to setting him loose to get the stage win he’s clearly eager to take.
From The Wall Street Journal ● Jul. 27, 2026
“Princess Mononoke” begins with a worm-covered demon attacking a pastoral village, only to be slain by its prince, Ashitaka.
From Salon ● Jul. 22, 2026
But to put the healthcare demon in context: According to federal government data, average annual healthcare costs for those over 65 are currently less than $8,000 a year per person.
From MarketWatch ● Jul. 17, 2026
These systems support rapid feedback, highly efficient detection, and have already been used to implement quantum versions of Maxwell's demon.
From Science Daily ● Jul. 3, 2026
Towering above them, looking like a demon, was the robot.
From "The Wild Robot Escapes" by Peter Brown
“Supernatural,” the demon- and monster-hunting drama that will not die, is back for the 13th season.
From Los Angeles Times ● Oct. 6, 2017
Kyle Green of Wasilla got $49,300 to build a demon- stration solar house suitable for northern latitudes.
From Time Magazine Archive
The Principle of divine metaphysics 111:12 is God; the practice of divine metaphysics is the utiliza- tion of the power of Truth over error; its rules demon- strate its Science.
From Science and Health, with Key to the Scriptures by Mary Baker Eddy
It crowned the demon- 243:9 strations of Jesus with unsurpassed power and love.
From Science and Health, with Key to the Scriptures by Mary Baker Eddy
By the substitution of Truth demon- strated, Science remedies the ills of material beliefs.
From Miscellaneous Writings, 1883-1896 by Mary Baker Eddy
Dan Sullivan — and, no, it’s not about a candidate living a double life or wrestling demons within himself.
From Los Angeles Times ● Jul. 12, 2026
His Othello is hounded into a betrayal of his probity and hard-earned honor not just by the villainy of Iago but by the demons of his past.
From The Wall Street Journal ● Jul. 9, 2026
Bowling an immaculate line and using the demons in the pitch, Archer unnerved Devon Conway with a blow to the helmet and, four balls later, had the left-hander fend to second slip.
From BBC ● Jun. 27, 2026
The Sunnydale gang fought monsters and demons, even dating a few.
From Salon ● Jun. 12, 2026
Like the demons who believe in God, I had accepted my fate.
From "Everything Sad Is Untrue" by Daniel Nayeri
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
