mysterious
1. [ adjective ] of an obscure nature
Synonyms: cryptic inscrutable mystifying deep cryptical
Examples:

"the new insurance policy is written without cryptic or mysterious terms" "a deep dark secret" "the inscrutable workings of Providence" "rituals totally mystifying to visitors from other lands"

Related terms: inexplicable
2. [ adjective ] having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding
Synonyms: mystic secret occult orphic mystical
Examples:

"mysterious symbols" "the mystical style of Blake" "occult lore" "the secret learning of the ancients"

Related terms: esoteric
Similar spelling:   mysteriously
  mystery
  mycteria
  mystery_story
  mystery_novel