# nightmare

/ˈnaɪtˌmɛɹ/ (US) · /nˈaɪtmeə/ (UK)

Source: https://englishreference.com/word/nightmare
Updated: 2026-06-19

## Senses

### 1. a scary dream

noun · CEFR B1

a very frightening or upsetting dream that happens while you are asleep.

For teachers: a distressing or terrifying dream that typically causes the sleeper to wake suddenly in a state of anxiety.

- The child woke up crying after having a nightmare about getting lost.
- Recurrent nightmares are often cited as a primary symptom of post-traumatic stress, frequently disrupting the patient's REM cycle and overall sleep quality.

### 2. a bad situation

noun · CEFR B2 · Informal

a very difficult, unpleasant, or disorganized situation in real life.

For teachers: a metaphorically terrifying or extremely unpleasant experience, often characterized by chaos, frustration, or bureaucratic difficulty.

- The traffic was a total nightmare and it took us three hours to get home.
- Navigating the legal requirements for the international merger proved to be a bureaucratic nightmare that exhausted the company's legal department.

### 3. a sleep demon

noun · CEFR C2 · Archaic · Literary

in old stories, a monster or spirit that people believed sat on them while they slept.

For teachers: a malevolent spirit or monster in folklore formerly believed to produce a feeling of suffocation in sleeping victims.

- Ancient legends spoke of a nightmare that would haunt the village at night.
- The painting depicts the nightmare as a heavy, crouched creature sitting upon the chest of a sleeping woman, reflecting eighteenth-century superstitions regarding sleep paralysis.

## Examples

- He sometimes has nightmares about the accident.
- Losing my passport while traveling abroad was a complete nightmare.
- For the team, the project became a logistical nightmare, tangled in regulations that seemed to change weekly.

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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.