Dictionary.com
Thesaurus.com
Synonyms

mysterious

American  
[mi-steer-ee-uhs] / mɪˈstɪər i əs /

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 British  
/ mɪˈstɪərɪəs /

adjective

  1. characterized by or indicative of mystery

  2. puzzling, curious, or enigmatic

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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

Etymology

Origin of mysterious

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

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.

Keep Reading on Vocabulary.com

Vocabulary lists containing mysterious

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.

See Examples For:

Her energy rises and falls alongside the mysterious mist, which has engulfed the city and brought whispers of a mysterious ancient entity lurking in its haze.

From Salon Aug. 17, 2026

That difference has raised an important question: What happens to these mysterious objects as the universe grows older?

From Science Daily Aug. 17, 2026

Set in Egypt during the 1930s and ’40s, the first entry in Lawrence Durrell’s Alexandria Quartet is a tragic romance between an impoverished Irish writer and the beautiful, mysterious Justine.

From The Wall Street Journal Aug. 17, 2026

Something mysterious has been happening in the world of secondhand books.

From BBC Aug. 15, 2026

He fell asleep watching the silent green boughs of the First Tree, while Wolf sped out of the cave on some mysterious errand of his own.

From "Wolf Brother" by Michelle Paver

Vocabulary.com logo
by dictionary.com

Join 12,000,000 vocabulary learners

Start learning new words today on VocabTrainer.
You'll remember them forever.

Start training