mysterious
Americanadjective
-
full of, characterized by, or involving mystery.
a mysterious occurrence.
-
implying or suggesting a mystery.
a mysterious smile.
-
of obscure nature, meaning, origin, etc.; puzzling; inexplicable.
a mysterious inscription on the ancient tomb.
- Synonyms:
- impenetrable, enigmatic, incomprehensible, unintelligible, unfathomable
adjective
-
characterized by or indicative of mystery
-
puzzling, curious, or enigmatic
Related Words
Mysterious, inscrutable, mystical, obscure refer to that which is not easily comprehended or explained. That which is mysterious, by being unknown or puzzling, excites curiosity, amazement, or awe: a mysterious disease. Inscrutable applies to that which is impenetrable, so enigmatic that one cannot interpret its significance: an inscrutable smile. That which is mystical has a secret significance, such as that attaching to certain rites or signs: mystical symbols. That which is obscure is discovered or comprehended dimly or with difficulty: obscure motives.
Other Word Forms
- mysteriously adverb
- mysteriousness noun
- quasi-mysterious adjective
- quasi-mysteriously adverb
- unmysterious adjective
- unmysteriously adverb
- unmysteriousness noun
Etymology
Origin of mysterious
Explanation
Something that is mysterious has a secret-like quality that makes it hard to understand or define, like your mysterious answers that made your friends curious about what you were really up to. A dark shadow skims across the surface of lake...a strange disease makes a city's inhabitants violently ill...a large, hairy creature is spotted wandering in the woods. These situations are all mysterious because we don't know their causes. You can see the word mystery in mysterious. A mystery is a hidden or secret thing, so something that is mysterious takes effort to understand, unless it is beyond our comprehension.
Vocabulary lists containing mysterious
Purple Hibiscus
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It's All a Blur: Synonyms for "Unclear"
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Schooled
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
At first glance, sea sponges seem almost too simple to be mysterious.
From Science Daily • Apr. 15, 2026
Finally, the hosts delve into the New York Times’ quest to uncover the mysterious creator of Bitcoin, the pseudonymous Satoshi Nakamoto, and argue over the investigation’s conclusion.
From Slate • Apr. 11, 2026
Unfounded claims that the Artemis II mission detected a mysterious moving object on the moon's surface also racked up millions of views across platforms.
From Barron's • Apr. 11, 2026
God may work in mysterious ways, but apparently he is still working.
From The Wall Street Journal • Apr. 8, 2026
She didn’t know why Mom had to be so mysterious about her past.
From "Caterpillar Summer" by Gillian McDunn
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
