mysterious

adjective

mys·​te·​ri·​ous mi-ˈstir-ē-əs 

1

a

: 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

mysteriousness noun

Synonyms

• arcane
• cryptic
• deep
• enigmatic
• enigmatical
• impenetrable
• inscrutable
• mystic
• occult
• uncanny

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.

Recent Examples on the Web

When the news first broke in the DRC, Michael Osterholm — director of the Center for Infectious Disease Research and Policy at the University of Minnesota — told NPR that this type of mysterious outbreak happens several times a year worldwide. —Gabrielle Emanuel, NPR, 31 Dec. 2024

As the two try to piece things together, a mysterious woman walks into the room holding a gun. —Yasmeen Hamadeh, People.com, 30 Dec. 2024

While many other annual meteor showers are caused by the debris trail of a comet, the origin of the Geminid shower is a little more mysterious. —Carlyn Kranking, Smithsonian Magazine, 30 Dec. 2024

While sightings are rare, this enigmatic predator remains a vivid reminder of the deep sea’s untamed and mysterious life forms. —Scott Travers, Forbes, 30 Dec. 2024

Word History

Etymology

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

First Known Use

1578, in the meaning defined at sense 1a

Phrases Containing mysterious

• be mysterious

Kids Definition

mysterious

adjective

mys·​te·​ri·​ous mis-ˈtir-ē-əs 

: containing, suggesting, or presenting a mystery

mysterious noises

also : difficult or impossible to understand

the mysterious ways of nature

mysteriously adverb