mystery >> ˈmɪst(ə)ri
Definition: [noun] something that is difficult or impossible to understand or explain.
Example: the mysteries of outer space
Definition: [noun] a novel, play, or film dealing with a puzzling crime, especially a murder.
Example: the 1920s murder mystery, The Ghost Train
Definition: [noun] the secret rites of Greek and Roman pagan religion, or of any ancient or tribal religion, to which only initiates are admitted.
Definition: [noun] a religious belief based on divine revelation, especially one regarded as beyond human understanding.
Example: the mystery of Christ