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.

Origin of mysterious

First recorded in 1610–20; mystery1 + -ous
Related formsmys·te·ri·ous·ly, adverbmys·te·ri·ous·ness, nounqua·si-mys·te·ri·ous, adjectivequa·si-mys·te·ri·ous·ly, adverbun·mys·te·ri·ous, adjectiveun·mys·te·ri·ous·ly, adverbun·mys·te·ri·ous·ness, noun

Synonyms for mysterious

Synonym study

1. 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. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for mysteriously

Contemporary Examples of mysteriously

Historical Examples of mysteriously

  • His eyes sought for sign of his goddess, who had disappeared most mysteriously.

  • Poets have been mysteriously silent on the subject of cheese.

    Alarms and Discursions

    G. K. Chesterton

  • He is mysteriously above as well as before you, by this fact, that he has died.

    A Dish Of Orts

    George MacDonald

  • Mrs. Blair's tones were mysteriously, ironically significant.

    The Innocent Adventuress

    Mary Hastings Bradley

  • "She wants you," said Primmie, mysteriously, her eyes shining with excitement.

    Galusha the Magnificent

    Joseph C. Lincoln

British Dictionary definitions for mysteriously



characterized by or indicative of mystery
puzzling, curious, or enigmatic
Derived Formsmysteriously, adverbmysteriousness, noun
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

Word Origin and History for mysteriously



1610s, "full of mystery," from Latin mysterium (see mystery (n.1)) + -ous. Related: Mysteriously; mysteriousness. Earlier in same sense was mysterial (early 15c.), from Late Latin mysterialis.

Online Etymology Dictionary, © 2010 Douglas Harper