nightmare

noun
night·​mare | \ ˈnīt-ˌmer 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

Keep scrolling for more

Other Words from nightmare

nightmare adjective
nightmarish \ ˈnīt-​ˌmer-​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

Visit the Thesaurus for More 

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

Running afoul of one of these laws can lead to a huge legal nightmare that takes years to untangle. Marisa Lascala, Good Housekeeping, "Everything You Need to Know About the Free-Range Parenting Method," 14 Mar. 2019 There’s a trailer to celebrate the occasion, complete with four-eyed penguins and some sort of spiky tentacle nightmare-creature. Hayden Dingman, PCWorld, "This week in games: The sordid tale of Starbreeze's stumbles, Overwatch players learn piano (with guns)," 1 Feb. 2019 Obtaining spider silk, however, is a bit of a nightmare, as most spider species are both extremely territorial and prone to cannibalism. John Timmer, Ars Technica, "Researchers insert a spider web gene into the silkworm," 8 Aug. 2018 The set designer Mimi Lien has created a bourgeois nightmare of a living room, complete with a polyester rug and a cute little dinette set. Hilton Als, The New Yorker, "With “Fairview,” Jackie Sibblies Drury Breaks the Fourth Wall," 24 June 2018 Évolution Is the Weirdest Sci-Fi Movie on Netflix A memorable surrealist nightmare, perfect for fans of Annihilation. Lincoln Michel, GQ, "Évolution Is the Weirdest Sci-Fi Movie on Netflix," 23 June 2018 And then Washington unleashed fury against Vegas on the wings of Evgeny Kuznetsov’s offense, Tom Wilson’s toughness and a Braden Holtby save that hockey fans will talk about—and Alex Tuch will have nightmares about—forever. Stephen Krupin, SI.com, "Capital Thrill: A Former Presidential Speechwriter Finally Gets to Pen His Dream Address," 11 June 2018 By all accounts, his life has been something of a nightmare ever since. Monique Judge, The Root, "Sure, Jan: Aaron Schlossberg’s Apology, Blacksplained," 22 May 2018 That's as good a first step toward digging out of the Orioles' nightmare start as any. Jon Meoli, baltimoresun.com, "Trumbo's 8th-inning single breaks tie, helps Orioles end 7-game slide by beating Royals, 5-3," 10 May 2018

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.

See More

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

Keep scrolling for more

Learn More about nightmare

Listen to Our Podcast about nightmare

Statistics for nightmare

Last Updated

14 Apr 2019

Look-up Popularity

Time Traveler for nightmare

The first known use of nightmare was in the 14th century

See more words from the same century

Keep scrolling for more

More Definitions for nightmare

nightmare

noun

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

nightmare

noun
night·​mare | \ ˈnīt-ˌmer How to pronounce nightmare (audio) \

Kids Definition of nightmare

1 : a frightening dream
2 : a horrible experience

Other Words from nightmare

nightmarish \ ˈnīt-​ˌmer-​ish \ adjective

nightmare

noun
night·​mare | \ ˈnīt-ˌma(ə)r, -ˌme(ə)r How to pronounce nightmare (audio) \

Medical Definition of nightmare

: a frightening or distressing dream that usually awakens the sleeper

Keep scrolling for more

Comments on nightmare

What made you want to look up nightmare? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to move or proceed with twists and turns

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Latin Quiz

  • roman forum
  • Which of the following months comes from a Latin word for “ten”?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!