mysterious

[ mi-steer-ee-uhs ]

adjective

1. full of, characterized by, or involving mystery:

   a mysterious occurrence.

   Synonyms: cryptic, occult, esoteric, secret

2. implying or suggesting a mystery:

   a mysterious smile.

3. of obscure nature, meaning, origin, etc.; puzzling; inexplicable:

   a mysterious inscription on the ancient tomb.

   Synonyms: impenetrable, enigmatic, incomprehensible, unintelligible, unfathomable

mysterious

/ mɪˈstɪərɪəs /

adjective

1. characterized by or indicative of mystery
2. puzzling, curious, or enigmatic

Derived Forms

• mysˈteriously, adverb
• mysˈteriousness, noun

Other Words From

• mys·teri·ous·ly adverb
• mys·teri·ous·ness noun
• quasi-mys·teri·ous adjective
• quasi-mys·teri·ous·ly adverb
• unmys·teri·ous adjective
• unmys·teri·ous·ly adverb
• unmys·teri·ous·ness noun

Word History and Origins

Origin of mysterious¹

First recorded in 1610–20; mystery ¹ + -ous

Synonym Study

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.

Example Sentences

Something mysterious may help tip our minds from waking life into slumber.

From Quanta Magazine

By all accounts, Riddler Nation had a lot of fun hunting for the mysterious numbers a few weeks back.

From FiveThirtyEight

She goes back to this mysterious place and then we get her ashes.

From Freakonomics

Plenty of questions remain about mysterious matter and forces, about the beginnings and the end of the universe, about how the science of the big meshes with quantum mechanics, the science of the very small.

From Science News

This mysterious ability to hop into someone else’s head—heck, even just to admit that they’re conscious beings with their own minds—is dubbed the “theory of mind.”

From Singularity Hub 

“Vicious pecking, avian hysteria, mysterious deaths, and even cannibalism” are the results, he writes.

From The Daily Beast

Perhaps the mysterious Martian methane, and its strange fluctuations, are part of that story.

From The Daily Beast

That reactivity paradoxically is what makes its sudden coming and going mysterious.

From The Daily Beast

Part of that was due to the elimination of the Mysterious Man.

From The Daily Beast

Like Fosse did with Cabaret, Marshall excised two major characters: the Narrator and the Mysterious Man.

From The Daily Beast

The explanation of his mysterious earlier moods offered itself with a clarity that was ghastly.

From Project Gutenberg

Lawrence handed the General the mysterious message and Schofield read it with a darkened brow.

From Project Gutenberg

This short interval had more than sufficed for De Lucenay's mysterious operations.

From Project Gutenberg

After all she, Hilda, possessed some mysterious characteristic more potent than the elegance and the goodness of Janet Orgreave.

From Project Gutenberg

Between each group of figures the face of the rock was scored with mysterious signs and rudely limned weapons of war and chase.

From Project Gutenberg

Related Words

• baffling
• cryptic
• curious
• dark
• enigmatic
• inexplicable
• inscrutable
• magical
• mystical
• mystifying
• obscure
• perplexing
• puzzling
• secretive
• strange
• unknown
• weird