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
Synonym Usage
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
Derived Forms
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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
It's All a Blur: Synonyms for "Unclear"
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Schooled
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
Astronomers have traced a mysterious type of repeating cosmic signal to an unusual pair of stars, providing the strongest evidence yet for the source of one of astronomy's most puzzling phenomena.
From Science Daily • Jun. 2, 2026
Eye movement desensitization and reprocessing, or EMDR, is so mysterious that even its trained practitioners don’t fully understand how it works.
From The Wall Street Journal • May 29, 2026
Esmeralda is there for some mysterious reasons that I’m trying to figure out.
From Los Angeles Times • May 26, 2026
On the ocean floor near the Galapagos Islands, a submersible controlled by scientists came across a mysterious octopus as blue as the ocean and no bigger than a golf ball.
From Barron's • May 25, 2026
That night, after Josie’s father and the mysterious woman went away, Josie meant to quietly burrow deeper into the blankets and fall asleep until morning.
From "The School for Whatnots" by Margaret Peterson Haddix
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.
