# demon

/ˈdimən/ (US) · /dˈiːmən/ (UK)

Source: https://englishreference.com/word/demon
Updated: 2026-08-15

## Senses

### 1. evil spirit

noun · CEFR B2

an evil spirit or supernatural being in stories and religion.

For teachers: an evil supernatural being or spirit, typically associated with hell or malevolence.

- In the old story, a brave knight fights a demon to save the village.
- The cathedral's architecture featured stone gargoyles intended to represent the demons that the faithful were taught to fear.

### 2. inner struggle

noun · CEFR B2

a strong, painful feeling or a bad habit that is hard to control.

For teachers: a source of persistent psychological torment, distress, or a destructive personal habit.

- The retired athlete struggled with his own demons after his career ended.
- The biography explores how the artist battled his inner demons through his work, often painting late into the night to escape his anxiety.

### 3. skilled person

noun · CEFR C1 · Informal

someone who does something with a lot of energy, speed, or skill.

For teachers: a person who performs a particular activity with great enthusiasm, energy, or technical proficiency.

- She is a demon on the tennis court and rarely loses a match.
- Known as a demon for detail, the editor spent weeks ensuring every citation in the manuscript was perfectly formatted.

### 4. computing process

noun · CEFR C1 · Technical

a background program on a computer that handles specific tasks without the user seeing it.

For teachers: a background process that handles system tasks or requests without direct user intervention; often spelled 'daemon'.

- The print demon handles all the documents you send to the printer.
- The system administrator noticed that a rogue demon was consuming excessive CPU cycles, slowing down the entire server network.

### 5. physics thought experiment

noun · CEFR C2 · Technical

an imaginary creature used in science to explain how energy and heat work.

For teachers: a hypothetical being used in thought experiments to illustrate physical laws, most notably Maxwell's demon.

- Maxwell's demon is a famous idea used to talk about the laws of physics.
- The professor used the concept of Maxwell's demon to challenge the students' understanding of the second law of thermodynamics.

## Examples

- The hero in the story fights a powerful demon.
- The ancient legends describe a demon that guards the entrance to the cave and tricks travelers.
- While the novel features literal monsters, the protagonist's true struggle is with the internal demons of guilt and regret that haunt his every decision.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.