- The definition of mysterious is something that is not understood or known.
An example of something mysterious is an old man who lives in a house and never comes outside.
Origin of mysterious; from Classical Latin mysterium (see mystery) + -ous
- Of, relating to, or being a religious mystery: mysterious and infinite truths.
- Arousing wonder or curiosity, especially by being difficult to explain or understand: the mysterious disappearance of the relevant files.
Origin of mysteriousFrench mystérieux, from mystère, secret, from Latin mystērium; see mystery1.
(comparative more mysterious, superlative most mysterious)
- Of unknown origin
- Having unknown qualities