Mys*te"ri*ous (?), a. [F.
mystèrieux. See 1st Mystery.] Of or
pertaining to mystery; containing a mystery; difficult or impossible
to understand; obscure; not revealed or explained; enigmatical;
incomprehensible.
God at last
To Satan, first in sin, his doom applied,
Thought in mysterious terms.
Milton.
Syn. -- Obscure; secret; occult; dark; mystic; cabalistic;
enigmatical; unintelligible; incomprehensible.