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Synonyms

nightmarish

American  
[nahyt-mair-ish] / ˈnaɪtˌmɛər ɪʃ /

adjective

  1. resembling a nightmare, especially in being terrifying, exasperating, or the like.

    his nightmarish experience in a concentration camp.


Other Word Forms

Etymology

Origin of nightmarish

First recorded in 1825–35; nightmare + -ish 1

Explanation

Something nightmarish is truly horrifying, something that would show up in a bad dream. Your nightmarish day might start with a car accident on the way to school and end with a fight with your best friend. A chilling scream in the middle of the night is nightmarish, and traumatic experiences like an episode of bullying or nearly stumbling off the top of a cliff would also be nightmarish. You can also use this adjective to emphasize the unpleasantness of an experience in a slightly exaggerated way: "Ugh, that math test was absolutely nightmarish." Nightmarish things resemble nightmares, or terrifying dreams.

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Vocabulary lists containing nightmarish

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The attempt went relatively smoothly, she explains, apart from a "nightmarish" section when cleaning a kid's playground at four in the morning where the game's bright primary colours affected her in "a very psychedelic way".

From BBC • Apr. 3, 2026

By then, a dream start and 36-31 halftime lead, had settled into a nightmarish second half for USC.

From Los Angeles Times • Feb. 28, 2026

It also extended a nightmarish stretch of Olympic finishes in Shiffrin’s otherwise outstanding career.

From The Wall Street Journal • Feb. 10, 2026

The author also announced in the statement that he’s been working on a book throughout the “strange, turbulent and occasionally nightmarish year and a half.”

From Los Angeles Times • Feb. 2, 2026

The master had said it in so many words—my reward for whatever awaited me in this nightmarish new world into which I had enlisted.

From "Flying Through Water" by Mamle Wolo