mys·te·ri·ous | \ mis-ˈtir-ē-əs \

Definition of mysterious 

1a : of, relating to, or constituting mystery the mysterious ways of God

b : exciting wonder, curiosity, or surprise while baffling efforts to comprehend or identify : mystifying heard a mysterious noise a mysterious stranger a mysterious plane crash a mysterious illness

2 : stirred by or attracted to the inexplicable … to help a mysterious wizard … ward off the end of the world with blood sacrifices. —Robert Houston

Keep scrolling for more

Other words from mysterious

mysteriously adverb
mysteriousness noun

Examples of mysterious in a Sentence

the mysterious ways of nature We heard a mysterious noise outside our tent. He died under mysterious circumstances. A mysterious illness has been spreading through the city. There's something mysterious about that old woman. Her behavior was very mysterious.
See More

Recent Examples on the Web

While 40 percent of cases are caused by known, preventable factors, the rest remain mysterious, frustrating scientists. NBC News, "Johnson & Johnson talc verdict goes against what is known about cancer," 13 July 2018 To make things even more mysterious, less than an hour later, the model finally tweeted confirmation of her and Justin's engagement. Andrea Park, Teen Vogue, "Justin Bieber Posts and Immediately Deletes Video of Hailey Baldwin Singing Rihanna," 13 July 2018 Though not much else is known, the mysterious Who is America? Jennie Neufeld, Vox, "Sarah Palin was “duped” by Sacha Baron Cohen for his new series," 11 July 2018 Charlton Heston led a big cast including James Stewart as a mysterious (but not sinister) clown. Joy Wallace Dickinson,, "Keep cool with movies linked to Florida’s past," 8 July 2018 For instance, a Gemini's Tinder profile may show a creative, mysterious, and independent persona that is highly attractive — and likely, highly curated. Sophie Saint Thomas, Allure, "What Your Zodiac Sign Says About Your Online Dating Style," 6 July 2018 From the beginning of her husband’s term, First Lady Melania Trump has been mysterious, private to the point of secretive, seldom seen and even less often heard. Molly Ball, Time, "Melania Trump Is Redefining One of the World’s Weirdest Jobs," 28 June 2018 Park’s people and even the occasional animals (a bird, a monkey) are energetic and mysterious, sinister and sly, with independent minds and complicated pasts. Mary Carole Mccauley,, "Artists explore American identity in Sondheim Artscape Prize exhibit," 21 June 2018 But the case remains mysterious, not least of all because two other European libraries have been affected by strikingly similar thefts. Brigit Katz, Smithsonian, "Stolen Christopher Columbus Letter Returned to Vatican, But Mystery Persists," 19 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mysterious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of mysterious

1578, in the meaning defined at sense 1a

History and Etymology for mysterious

mystery entry 1 + -ous, probably after Middle French mysterieux

Keep scrolling for more

Learn More about mysterious

Share mysterious

Phrases Related to mysterious

be mysterious

Statistics for mysterious

Last Updated

30 Aug 2018

Look-up Popularity

Time Traveler for mysterious

The first known use of mysterious was in 1578

See more words from the same year

Keep scrolling for more

More Definitions for mysterious



English Language Learners Definition of mysterious

: strange, unknown, or difficult to understand


mys·te·ri·ous | \ mi-ˈstir-ē-əs \

Kids Definition of mysterious

: strange, unknown, or hard to understand or explain a mysterious noise a mysterious stranger

Other words from mysterious

mysteriously adverb She mysteriously disappeared.
mysteriousness noun

Keep scrolling for more

Comments on mysterious

What made you want to look up mysterious? Please tell us where you read or heard it (including the quote, if possible).


an open space surrounded by woods

Get Word of the Day daily email!

Test Your Vocabulary

Name that Food Quiz

Name That Thing

Test your visual vocabulary with our 10-question challenge!


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!