mysterious

adjective

mys·​te·​ri·​ous mi-ˈstir-ē-əs How to pronounce mysterious (audio)
Synonyms of mysterious
1
a
: of, relating to, or constituting mystery
the mysterious ways of God
b
: exciting wonder, curiosity, or surprise while baffling efforts to comprehend or identify : mystifying
heard a mysterious noise
a mysterious stranger
a mysterious plane crash
a mysterious illness
2
: stirred by or attracted to the inexplicable
… to help a mysterious wizard … ward off the end of the world …—Robert Houston
mysteriousness noun

Synonyms of mysterious

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Examples of mysterious in a Sentence

the mysterious ways of nature We heard a mysterious noise outside our tent. He died under mysterious circumstances. A mysterious illness has been spreading through the city. There's something mysterious about that old woman. Her behavior was very mysterious.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In January 2005, the European Space Agency’s Huygens probe — carried to Saturn by NASA’s Cassini spacecraft — became the first and only spacecraft to land on the mysterious moon. — Jamie Carter, Forbes.com, 18 Aug. 2026 Made under the mentorship of indie legend Alexandre Rockwell (In the Soup, Four Rooms) and shot in Osubor’s hometown of Providence, Rhode Island, the genre efforts follows a flower delivery driver drawn into the world of a mysterious crime boss. — Scott Roxborough, HollywoodReporter, 18 Aug. 2026 The mysterious wounds found on one of the world's oldest orcas have triggered an investigation in Spain and raised questions about whether someone took aim at the famed killer whale amid years of tense encounters between orcas and boats. — Stepheny Price, FOXNews.com, 18 Aug. 2026 Hal is arrested, per his plan, as John meets and sleeps with a mysterious woman, Zoe (Poorna Jagannathan), and uses Hal’s ring to light her cigarette after the fact. — Siddhant Adlakha, Vulture, 17 Aug. 2026 See All Example Sentences for mysterious

Word History

Etymology

mystery entry 1 + -ous, probably after Middle French mysterieux

First Known Use

1578, in the meaning defined at sense 1a

Time Traveler
The first known use of mysterious was in 1578

Phrases Containing mysterious

Rhymes for mysterious

See All Rhymes for mysterious

Browse Nearby Words

mysteriosophy
mysterious
mysteriously
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Cite this Entry

“Mysterious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mysterious. Accessed 23 Aug. 2026.

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Kids Definition

mysterious

adjective
mys·​te·​ri·​ous mis-ˈtir-ē-əs How to pronounce mysterious (audio)
: containing, suggesting, or presenting a mystery
mysterious noises
also : difficult or impossible to understand
the mysterious ways of nature
mysteriously adverb

More from Merriam-Webster on mysterious

Nglish: Translation of mysterious for Spanish Speakers

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