nightmare

noun

night·mare | \ ˈnīt-ˌmer

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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Synonyms & Antonyms for nightmare

Synonyms

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

Antonyms

heaven, paradise

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

To borrow from Beyoncé (herself no stranger to musicals and iconicity), Rodarte trades in both sweet dreams and beautiful nightmares. — Nicole Phelps, Vogue, "The Top 10 Collections of the Fall 2019 Season," 8 Mar. 2019 So there’s effectively six hours of ungoverned time in the residence with a television and a phone, and this is like John Kelly’s worst nightmare. — Eric Johnson, Recode, "Axios’ Jonathan Swan explains what the press gets wrong about the Trump administration," 6 Dec. 2018 Sharing an Instagram account with a lover sounds like a nightmare, but some lost souls are doing it, Emily Dreyfuss reports, who is now one of those souls. — Casey Newton, The Verge, "Facebook should help us understand the link between political speech and violence," 23 Aug. 2018 Biggest Surprise: Ridley, the giant dragon alien baddie from Metroid, is coming to Smash Bros, which seems like a logistical nightmare for the developers. — Julie Muncy, WIRED, "The Biggest Surprises (and Missed Opportunities) of the E3 Press Conferences," 12 June 2018 Even after Nashville Yards opens, the rest of downtown will still look like an orthodontist’s nightmare: more gap than shine. — Justin Davidson, Daily Intelligencer, "Downtown Nashville Is Supposed to Be the Model of the Walkable 21st-Century City. I’m Not So Sure.," 8 June 2018 It’s Over Award Our long national nightmare of media speculation and mayoral grovelling ends with HQ2 split between New York and Washington. — Mark Lamster, Curbed, "2018 in architecture: The good, the bad, and the urbanism," 27 Dec. 2018 It's been more than a year since Pennywise first came to haunt our nightmares, and thanks to the impending arrival of Halloween, the *It costume inspiration has returned, sort of. — Lauren Rearick, Teen Vogue, "Makeup Artist Shared His Halloween Beauty Routine for a Pennywise from “It” Look," 9 Oct. 2018 My worst nightmare was becoming a terrifying reality. — Yasmine Koenig As Told To Liz Welch, Seventeen, "My Mom Took Me Overseas and Forced Me Into Being a Teen Bride," 26 Sep. 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.