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

At long last, their two-month nightmare was finally over. — Jordan Culver, Pro Soccer USA, "Orlando City earns 2-1 win over Toronto FC, snaps nine-match MLS losing skid," 14 July 2018 Get our daily newsletter Your immediate nightmare is the flotation process, which is a cross between an election campaign, a show trial and an Ironman event. — The Economist, "Life as you know it is IPOver," 12 July 2018 So what can Democrats do to stop their nightmare from becoming a reality? — Margaret Hartmann, Daily Intelligencer, "Democrats Scolded For Misusing Mitch McConnell’s Made Up Supreme Court Rule," 28 June 2018 More than one person has blamed their nightmares on watching a scary movie late at night. — Louise Matsakis, WIRED, "Do You Dream in Internet? Don’t Freak Out," 23 June 2018 My worst nightmare was that my mother would be deported and I would be left alone with no one to turn to. — Catalina Cruz, Marie Claire, "I'm a DREAMer Who Grew Up Undocumented, Poor, and Terrified. That's Why I'm Running for Office.," 22 June 2018 Throw in an overbearing boss, his nightmare of a 10-year-old son, and his wife who keeps it all together by breaking things apart. — Denise Coffey, Courant Community, "Situation Comedy "The Nerd" Opens At Bradley Playhouse," 11 June 2018 Think of how Freddy Krueger went from an elemental, primal terror literally out of your nightmares to a wisecracking ghoul over the course of the Nightmare on Elm Street films. — Todd Vanderwerff, Vox, "5 things to know about Jurassic World: Fallen Kingdom," 5 June 2018 As a Philadelphia Eagles fan, this past Super Bowl Sunday should have been one of the best days of Rasaan Urquhart's life — but the late-night celebrations quickly turned into a nightmare for the 25-year-old. — Jennifer Earl, Fox News, "Philadelphia man partly blinded by fireworks shares harrowing story to warn Fourth of July revelers," 4 July 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.