1. A story about a crime (usually murder) presented as a novel or play or movie; SYN. mystery story, whodunit.
2. Something that baffles understanding and cannot be explained; SYN. enigma, secret, closed book.

ETYM French secret (cf. Pr. secret, Spanish and Portu. secreto, Italian secreto, segreto), from Latin secretum. Related to Secret.
1. Information known only to a special group; SYN. arcanum.
2. Something that should remain hidden from others (especially information that is not to be passed on).