What does "nightmare" mean?
A very unpleasant or frightening dream.
Nightmare
/ˈnaɪt.mɛə/ noun, verb
noun, verb ·Moderate ·High school level
Meaning at a glance
- Primary sense: A very unpleasant or frightening dream.
- Grammar: nightmare is listed as noun, verb.
- Nearest alternatives: appalling, bad dream, bad dream, bete noire.
- Useful contrasts: advantageous, benign, comforting.
- Usage evidence: I feel as if I've woken up from a nightmare.
How to use "nightmare"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "nightmare" carries the exact meaning, tone, and strength you need.
- Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.
Meaning check
- Does the word fit the sentence's grammar?
- Does it match the intended tone rather than only the dictionary definition?
- Would a simpler synonym be clearer for the reader?
- Is there enough surrounding context to prevent ambiguity?
Source and review context
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "nightmare" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Before you rely on this definition
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "nightmare" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "nightmare" with a nearby alternative so the final choice matches both meaning and reader expectation.
Compare nearby meanings
- Use synonyms when you need a softer, stronger, simpler, or more specific word.
- Use antonyms to check the boundary of the meaning and avoid accidental contrast.
- Use the example sentence to confirm the word behaves naturally in context.
- Keep the original wording when a replacement adds complexity without improving precision.
Definition decision workflow
1. Identify the role
Check whether "nightmare" is acting as noun, verb in your sentence. A definition is only useful when the grammar matches the way the word is being used.
2. Test the nearest option
Compare it with "appalling" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
3. Confirm with context
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Final meaning check
Before publishing a sentence with "nightmare", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
Definitions
Noun
- 1 A very unpleasant or frightening dream.
"I had a nightmare that I tried to run but could neither move nor breathe."
- 2 a terrifying or deeply upsetting dream wordnet
- 3 Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure. figuratively
"Cleaning up after identity theft can be a nightmare of phone calls and letters."
- 4 a situation resembling a terrifying dream wordnet
- 5 A demon or monster, thought to plague people while they slept and cause a feeling of suffocation and terror during sleep. archaic
"It haunted me, however, more than once, like a night-mare."
Show 1 more definition
- 6 A feeling of extreme anxiety or suffocation experienced during sleep; sleep paralysis. historical
"The Night-mare generally ſeizes people ſleeping on their backs, and often begins with frightful dreams, which are ſoon ſucceeded by a difficult reſpiration, a violent oppreſſion on the breaſt, and a total privation of voluntary motion."
Verb
- 1 To experience a nightmare. intransitive
"Brother Fary of Omaha was nightmaring the rest of the night."
- 2 To imagine (someone or something) as in a nightmare. transitive
"She was the last person I’d expected to see, although I had not expected to see anyone at all. For a moment I thought it was a nightmare, and that I was nightmaring the whole thing."
- 3 To trouble (someone or something), as by a nightmare. transitive
"THe day is broke! Melpomene, be gone; / Hag of my Fancy, let me now alone: / Night-mare my ſoul no more; Go take thy flight / Where Traytors Ghoſts keep an eternal night; […]"
Synonyms
All synonymsAntonyms
Example
"I feel as if I've woken up from a nightmare."
Common questions
What is a synonym for "nightmare"?
Common synonyms include: appalling, bad dream, bad dream, bete noire, bogey, bogeyman.
How do you use "nightmare" in a sentence?
I feel as if I've woken up from a nightmare.
How do you pronounce "nightmare"?
Pronounced /ˈnaɪt.mɛə/.
Etymology
From Middle English nyghtmare, from Old English *nihtmare, equivalent to night + mare (“evil spirit believed to afflict a sleeping person”). Cognate with Scots nichtmare and nichtmeer, Dutch nachtmerrie, Middle Low German nachtmār, German Nachtmahr.