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.
Black holes are among the most mysterious objects in the cosmos. — Kaif Shaikh, Interesting Engineering, 29 June 2026 The movie is set in a 13th-century English village and follows the townspeople as a mysterious, folkloric creature stalks their village. — Jason P. Frank, Vulture, 29 June 2026 Fantastical adventures ensue as the pair encounter a mysterious woman, Alexandra, who has lost her son, along with coyotes, bandits, and some pretty big secrets. — Jennifer Ouellette, ArsTechnica, 29 June 2026 Porzingis, who said last year he had been diagnosed with postural orthostatic tachycardia syndrome, missed two weeks shortly after the trade with a mysterious illness that was never publicly identified. — Joseph Dycus, Mercury News, 29 June 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

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Browse Nearby Words

mysteriosophy
mysterious
mysteriously
See all Nearby Words

Cite this Entry

“Mysterious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mysterious. Accessed 7 Jul. 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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