mystery, problem, enigma, riddle, puzzle mean something which baffles or perplexes. mystery applies to what cannot be fully understood by reason or less strictly to whatever resists or defies explanation. …

MYSTERY definition: anything that is kept secret or remains unexplained or unknown. See examples of mystery used in a sentence.

MYSTERY meaning: 1. something strange or not known that has not yet been explained or understood: 2. a book, film…. Learn more.

Definition of mystery noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

mystery noun Anything that arouses curiosity or perplexes because it is unexplained, inexplicable, or secret:

A mystery film is a film that revolves around the solution of a problem or a crime. It focuses on the efforts of the detective, private investigator or amateur sleuth to solve the mysterious circumstances of an …

Dec 11, 2025 · The Best Mystery Novels of 2025 Our columnist on the books that wowed her this year. Credit...Photo illustration by Sebastian Mast Share full article

Dec 14, 2025 · mystery (countable and uncountable, plural mysteries) The truth behind the events remains a mystery. The case was that of a murder. It had an element of mystery about it, however, …

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.

There are six meanings listed in OED's entry for the noun mystery, three of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.