something that is difficult or impossible to understand or explain
the mysteries of outer space
what happened after he left home that day remains a mystery
a novel, play, or film dealing with a puzzling crime, especially a murder
the 1920s murder mystery, The Ghost Train
the secret rites of Greek and Roman pagan religion, or of any ancient or tribal religion, to which only initiates are admitted
a religious belief based on divine revelation, especially one regarded as beyond human understanding
the mystery of Christ
a handicraft or trade, especially when referred to in indentures