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nightmare

noun
night·​mare | \ ˈnÄ«t-ËŒmer How to pronounce nightmare (audio) \

Definition of nightmare

1 : an evil spirit formerly thought to oppress people during sleep
2 : a frightening dream that usually awakens the sleeper
3 : something (such as an experience, situation, or object) having the monstrous character of a nightmare or producing a feeling of anxiety or terror
Other Words from nightmare Synonyms & Antonyms Did You Know? Example Sentences Learn More about nightmare

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Other Words from nightmare

nightmare adjective
nightmarish \ ˈnÄ«t-​ËŒmer-​ish How to pronounce nightmarish (audio) \ adjective
nightmarishly adverb

Synonyms & Antonyms for nightmare

Synonyms

agony, Gehenna, hell, horror, misery, murder, torment, torture

Antonyms

heaven, paradise

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Did You Know?

Looking at nightmare, you might guess that it is a compound formed from night and mare. If so, your guess is correct. But while the night in nightmare makes sense, the mare part is less obvious. Most English speakers know mare as a word for a female horse or similar equine animal, but the mare of nightmare is a different word, an obsolete one referring to an evil spirit that was once thought to produce feelings of suffocation in people while they slept. By the 14th century the mare was also known as a nightmare, and by the late 16th century nightmare was also being applied to the feelings of distress caused by the spirit, and then to frightening or unpleasant dreams.

Examples of nightmare in a Sentence

Mommy, I had a really scary nightmare. The party was a complete nightmare.

Recent Examples on the Web

 Koedderich and Wasilewski said their nightmare situation was a factor that led to their divorce. — CBS News, "White couple gives birth to Asian daughter after alleged fertility clinic mix-up," 12 Sep. 2019 Travis a force through the air The Raiders’ twice-yearly nightmare that is tight end Travis Kelce looms again. — Jon Becker, The Mercury News, "Focus on Kansas City: History says Raiders are doomed," 11 Sep. 2019 To say that the past 20 years has been a living nightmare would be a huge understatement! — Amy Dickinson, The Denver Post, "Ask Amy: Father-in-law wants to issue premarital warning," 10 Sep. 2019 To say that the past 20 years has been a living nightmare would be a huge understatement! — Ask Amy, oregonlive, "Ask Amy: Father wants to know if he should warn future son-in-law about daughter’s behavior," 10 Sep. 2019 The same words that encapsulated the widespread excitement over Kelly’s hiring now express the growing frustrations over the five-year, $23.3-million nightmare unfolding at the Rose Bowl. — Dylan Hernandez, Los Angeles Times, "Column: Under Chip Kelly, UCLA is making the wrong kind of history," 7 Sep. 2019 The wall was a magnificent nightmare of black rock and blue ice, soaring straight up into oblivion. — Nick Heil, Outside Online, "The Tragedy on Howse Peak," 28 Aug. 2019 Aside from the prospect of attacks on safety systems and the looming possibility of another NotPetya-style worm, plenty of other nightmare hypotheticals continue to trouble the sleep of cyberwar wonks. — Andy Greenberg, WIRED, "The WIRED Guide to Cyberwar," 23 Aug. 2019 The boys will spy on the teen couple next door, but the drone gets snagged, and the nightmare journey has just begun. — Ramona Sentinel, "Flickers: ‘Angel Has Fallen’ and ‘Overcomer’ open Friday," 20 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'nightmare.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of nightmare

14th century, in the meaning defined at sense 1

History and Etymology for nightmare

Middle English nyghte mare, from nyghte night entry 1 + mare mare entry 3

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More Definitions for nightmare

nightmare

noun
How to pronounce nightmare (audio)

English Language Learners Definition of nightmare

: a dream that frightens a sleeping person : a very bad dream
: a very bad or frightening experience or situation

See the full definition for nightmare in the English Language Learners Dictionary

nightmare

noun
night·​mare | \ ˈnÄ«t-ËŒmer How to pronounce nightmare (audio) \

Kids Definition of nightmare

1 : a frightening dream
2 : a horrible experience

Other Words from nightmare

nightmarish \ ˈnÄ«t-​ËŒmer-​ish \ adjective

nightmare

noun
night·​mare | \ ˈnÄ«t-ËŒma(É™)r, -ËŒme(É™)r How to pronounce nightmare (audio) \

Medical Definition of nightmare

: a frightening or distressing dream that usually awakens the sleeper

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More from Merriam-Webster on nightmare

Rhyming Dictionary: Words that rhyme with nightmare

Thesaurus: All synonyms and antonyms for nightmare

Spanish Central: Translation of nightmare

Nglish: Translation of nightmare for Spanish Speakers

Britannica English: Translation of nightmare for Arabic Speakers

Britannica.com: Encyclopedia article about nightmare

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