mysterious
adjective
mys·te·ri·ous
mi-ˈstir-ē-əs 
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
Robert Houston
mysteriousness
noun
Synonyms of mysterious
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
Brandon Aiyuk’s recent emergence on social media now includes his bluntest message yet about a mysterious estrangement with the 49ers.
—Cam Inman, Mercury News, 10 June 2026
Antineutrinos are equally mysterious, opposite versions of neutrinos that scientists can study to understand their behavior and how neutrinos work.
—ABC News, 10 June 2026
Clutching a mysterious tool the shape of a mouse coffin, Firth’s villain tracks Daniel’s location by mentally transplanting himself into another person’s body, changing the color of their pupils to his own icy blue.
—Amy Nicholson, Los Angeles Times, 10 June 2026
Led to a dead body after reading a mysterious email, Guard is framed for murder and sent to the airlock without a trial.
—Zackery Cuevas, PC Magazine, 10 June 2026
See All Example Sentences for mysterious
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.
Cam Inman, Mercury News, 10 June 2026
Antineutrinos are equally mysterious, opposite versions of neutrinos that scientists can study to understand their behavior and how neutrinos work.
—ABC News, 10 June 2026
Clutching a mysterious tool the shape of a mouse coffin, Firth’s villain tracks Daniel’s location by mentally transplanting himself into another person’s body, changing the color of their pupils to his own icy blue.
—Amy Nicholson, Los Angeles Times, 10 June 2026
Led to a dead body after reading a mysterious email, Guard is framed for murder and sent to the airlock without a trial.
—Zackery Cuevas, PC Magazine, 10 June 2026
See All Example Sentences for mysterious
Cite this Entry
“Mysterious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mysterious. Accessed 14 Jun. 2026.
Copy CitationKids Definition
mysterious
adjective
mys·te·ri·ous
mis-ˈtir-ē-əs
: containing, suggesting, or presenting a mystery
mysterious noises
also
: difficult or impossible to understand
the mysterious ways of nature
mysteriously
adverb
Love words? Need even more definitions?
Merriam-Webster unabridged
