Each of these words refers to something that is not easily understood or explained. By being unknown or puzzling, that which is mysterious produces curiosity, awe, or amazement: "He is suffering from some mysterious illness that baffles the doctors." "She acted in a most mysterious way." That which is mythical involves a myth (a traditional or legendary story about superhuman beings) or is imaginary and without foundation: "His account of the trip was wholly mythical." "This tale about dragons and unicorns is a delightfully mythical narrative." Anything that is mystical has a secret significance or meaning: "These rites are a mystical symbol of brotherhood." "Many of Edgar Allan Poe's best stories are mystical." Related words include occult, secret, esoteric, cryptic, obscure, inscrutable, enigmatic, and puzzling.
Dictionary of problem words and expressions. Harry Shaw. 1975.