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

Relevance
See All Synonyms & Antonyms in Thesaurus

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.
As on television, Seyfried nails Holmes’s wide eyes, unsteady mannerisms, deep voice, and mysterious vocal cadence that makes the character both unreal and oddly human. — Jackson McHenry, Vulture, 17 Oct. 2026 Days into their expedition, the team searching for Amelia Earhart’s missing plane is battling severe weather — and racing to identify a mysterious object that could finally solve the aviator's disappearance. — Andrea Margolis, FOXNews.com, 16 Oct. 2026 Fans of the genre will be satisfied by the whodunit – the question of how something happened and the mysterious nature of it. — Jesse Whittock, Deadline, 16 Oct. 2026 Infiniti will next star in the mysterious horror feature Portrait of God from rising director Dylan Clark, who wrote the script with Joe Russo. — Etan Vlessing, HollywoodReporter, 16 Oct. 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
See all Nearby Words

Cite this Entry

“Mysterious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mysterious. Accessed 22 Oct. 2026.

Copy Citation

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
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of vocation

See Definitions and Examples »

Popular in Grammar & Usage

See More

Merriam-Webster’s Great Big List of Words You Love to Hate

'Can' vs. 'May'

'Affect' vs. 'Effect'

More Commonly Mispronounced Words

Is it 'nerve-racking' or 'nerve-wracking'?
See More

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

Did 'orange' the fruit or the color come first?

Even More Bird Names that Sound Like Insults (and Sometimes Are)

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

Merriam-Webster’s Great Big List of Words You Love to Hate

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
artwork of illustrated limes with the text limes and smile with an arrow connecting the two words
Quiz: Spot the Anagram! Scramble these words to find new words with the e...
See All