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