'Mysterious' definitions:

Definition of 'mysterious'

From: WordNet
adjective
Of an obscure nature; "the new insurance policy is written without cryptic or mysterious terms"; "a deep dark secret"; "the inscrutable 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" [syn: cryptic, cryptical, deep, inscrutable, mysterious, mystifying]
adjective
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" [syn: mysterious, mystic, mystical, occult, secret, orphic]

Definition of 'Mysterious'

From: GCIDE
  • Mysterious \Mys*te"ri*ous\, a. [F. myst[`e]rieux. See 1st Mystery.] Of or pertaining to mystery; containing a mystery; difficult or impossible to understand; inexplicable; obscure; not revealed or explained; enigmatical; incomprehensible. [1913 Webster]
  • God at last To Satan, first in sin, his doom applied, Thought in mysterious terms. --Milton. [1913 Webster]
  • Syn: Obscure; secret; occult; dark; mystic; cabalistic; enigmatical; unintelligible; inexplicable; incomprehensible. [1913 Webster]

Synonyms of 'mysterious'

From: Moby Thesaurus