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Showing results for mysterious. Search instead for phrase mysterious.
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

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

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

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.

The mysterious arson fires in a Hollywood neighborhood started small.

From Los Angeles Times • Apr. 1, 2026

After all, Vance had really just wanted to highlight religion, it would have made a little more sense to portray mysterious flying objects as angels, not demons.

From Salon • Apr. 1, 2026

Yet tourists might find themselves entirely alone at Cromeleque dos Almendres which along with the smaller and less-visited Cromeleque de Vale Maria do Meio are mysterious mini-Stonehenge circles of planted stone monoliths.

From The Wall Street Journal • Mar. 27, 2026

Researchers have uncovered how a mysterious ion channel helps cells break down waste, opening new possibilities for treating Parkinson's disease.

From Science Daily • Mar. 26, 2026

The mysterious massive object was shaped like a barrel topped with a platform and a jumble of structures.

From "The Wild Robot Protects" by Peter Brown