Of or pertaining to mystery; containing a mystery; difficult or impossible to understand; obscure; not revealed or explained; enigmatical; incomprehensible
If someone is mysterious about something, they deliberately do not talk much about it, sometimes because they want to make people more interested in it. As for his job -- well, he was very mysterious about it. + mysteriously mys·teri·ous·ly Asked what she meant, she said mysteriously: `Work it out for yourself'
Someone or something that is mysterious is strange and is not known about or understood. He died in mysterious circumstances A mysterious illness confined him to bed for over a month The whole thing seems very mysterious + mysteriously mys·teri·ous·ly A couple of messages had mysteriously disappeared
having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding; "mysterious symbols"; "the mystical style of Blake"; "occult lore"; "the secret learning of the ancients"
of an obscure nature; "the new insurance policy is written without cryptic or mysterious terms"; "a deep dark secret"; "the inscrutible workings of Providence"; "in its mysterious past it encompasses all the dim origins of life"- Rachel Carson; "rituals totally mystifying to visitors from other lands"