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Definition of nightmarish

nightmarish

/ˈnaɪtˌmɛər.ɪʃ/
night · mar · ish
Adverb:nightmarishly
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nightmarish Lexical Profile

nightmarish Game Scores & Validity

• adjective

1

Resembling or characteristic of a nightmare; extremely frightening, distressing, or unpleasant.

Example

"Navigating the flooded streets during the blackout proved to be a nightmarish experience for the commuters."

Synonyms
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Antonyms
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• Nearby Words

nightlong
nightly
nightmare
nightmarish
nightmarishly
nightmarishness
nightscape

Word Origin & Etymology

Formed in the early 19th century by adding the adjective-forming suffix '-ish' to 'nightmare', which originally referred in Old English folklore to an incubus or evil spirit ('mare') believed to sit on a sleeper's chest at night and cause suffocation.

Cite this Entry

Wordmom. (2026). Definition of Nightmarish. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/nightmarish
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