Other forms: mysteries
A mystery is something that cannot be explained, and by extension a story built around exactly that — usually who did it. A murder mystery, it is a mystery to me, solve the mystery.
As a genre label, mystery is the American term where British publishers say crime or detective fiction. It is countable for a puzzle and uncountable for the quality: an air of mystery. The adjective mysterious describes both things and people. Note that in the plural, mysteries also means secret religious rites — the Eleusinian mysteries — and medieval mystery plays, which were biblical dramas performed by trade guilds.
1nouncannotSomething that cannot be explained.
“How it got there is a complete mystery.”
2nounmysteryA story about solving a crime or a puzzle.
“She reads nothing but mysteries.”
3nounqualityA quality of being hard to know about.
“There is an air of mystery about the whole family.”
Too few real examples of this word to estimate which sense is commonest.
mystery is something unexplained.
Greek mysterion meant a secret rite, from mystes, one who has been initiated — from myein, to close the eyes or lips. A mystery is something you have been sworn not to tell, which is a stronger idea than something nobody knows.
Ancient Greek
μυστήριον — a mystery, a secret, a secret rite
Latin
mysterium
Anglo-Norman
misterie
Middle English
mysterie
English, today
mystery
Built from
From Middle English mysterie, from Anglo-Norman misterie (Old French mistere), from Latin mysterium, from Ancient Greek μυστήριον (“a mystery, a secret, a secret rite”), from μύστης (“initiated one”), from μυέω (“to initiate”), from μύω (“to shut”). Displaced native Old English ġerȳne.
Etymology from Wiktionary, CC BY-SA