mystery

¹ American  

[mis-tuh-ree, -tree] / ˈmɪs tə ri, -tri /

noun

plural

mysteries

1. anything that is kept secret or remains unexplained or unknown.

   the mysteries of nature.

2. any affair, thing, or person that presents features or qualities so obscure as to arouse curiosity or speculation.

   The masked guest is an absolute mystery to everyone.

3. a novel, short story, play, or film whose plot involves a crime or other event that remains puzzlingly unsettled until the very end.

   a mystery by Agatha Christie.

4. obscure, puzzling, or mysterious quality or character.

   the mystery of Mona Lisa's smile.

   Synonyms:

   secrecy, mystique, obscurity, ambiguity, riddle, secret, problem, puzzle, enigma

5. any truth that is unknowable except by divine revelation.

6. (in the Christian religion)

   1. a sacramental rite.

   2. Eucharist.

7. an incident or scene in connection with the life of Christ, regarded as of special significance.

   the mysteries of the Passion.

8. any of the 15 events in the lives of Christ and the Virgin Mary meditated upon during the recitation of the rosary.

9. mysteries,

   1. ancient religions that admitted candidates by secret rites and rituals the meaning of which was known only to initiated worshipers.

   2. any rites or secrets known only to those initiated.

      the mysteries of Freemasonry.

   3. (in the Christian religion) the Eucharistic elements.

10. mystery play.

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mystery ² American  

[mis-tuh-ree] / ˈmɪs tə ri /

noun

Archaic.

plural

mysteries

1. a craft or trade.

2. a guild, as of merchants.

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mystery ¹ British  

/ ˈmɪstərɪ, -trɪ /

noun

1. an unexplained or inexplicable event, phenomenon, etc

2. a person or thing that arouses curiosity or suspense because of an unknown, obscure, or enigmatic quality

3. the state or quality of being obscure, inexplicable, or enigmatic

4. a story, film, etc, which arouses suspense and curiosity because of facts concealed

5. Christianity any truth that is divinely revealed but otherwise unknowable

6. Christianity a sacramental rite, such as the Eucharist, or ( when plural ) the consecrated elements of the Eucharist

7. (often plural) any of various rites of certain ancient Mediterranean religions

8. short for mystery play

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mystery ² British  

/ ˈmɪstərɪ /

noun

1. a trade, occupation, or craft

2. a guild of craftsmen

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Etymology

Origin of mystery¹

First recorded in 1275–1325; Middle English misteri(e), from Latin mystērium “a secret,” (plural) mystēria “secret rites,” from Greek mystḗrion, equivalent to mýs(tēs) “an initiate (into the Eleusinian mysteries)” + -tērion noun suffix; mystic )

Origin of mystery²

First recorded in 1350–1400; Middle English misteri(e) “ministry, office; handicraft, art; guild” from Old French mistere and Medieval Latin misterium, variant of Latin ministerium ministry, confused with mystērium mystery ¹ ( def. )

Explanation

A mystery is something that baffles our understanding and cannot be explained. The giant slabs of Stonehenge, remain a mystery to this day. The noun mystery comes from the Greek mysterion, meaning "secret rite or doctrine." A great synonym for secret is enigma. We use this word all the time to describe stuff we don't understand, from crop circles and UFOs to the origins of the universe and the workings of the human brain. In literature, drama, and film, a mystery is a story that centers around a crime, usually murder, which finally gets solved at the very end.

Example Sentences

Consumers encountered voice AI at 5% of restaurant-chain drive-throughs last year, up from 4% in 2024, according to research firm Intouch Insight, which sends mystery shoppers to test drive-throughs.

From The Wall Street Journal • Apr. 16, 2026

For mystery writers, who often write quickly for people who like to read quickly, doing stand-alones might be considered a disadvantage.

From Los Angeles Times • Apr. 16, 2026

A new fossil discovery is bringing fresh insight into one of the most remarkable survival stories in Earth's history while also resolving a scientific mystery that has puzzled researchers for decades.

From Science Daily • Apr. 14, 2026

A baby boy whose skeleton was found beneath floorboards could have died up to 300 years ago, an inquest has heard, adding more mystery to what happened to him.

From BBC • Apr. 14, 2026

A bunch of the cans are gross—covered in dirt or leaves, dripping mystery liquids.

From "Wayward Creatures" by Dayna Lorentz

Related Words

• conundrum
• enigma
• problem
• question
• riddle
• secrecy
• subtlety
• thriller