mysterious

adjective
mys*te*ri*ous \ mi-ˈstir-ē-əs \
1578{ds||1|a|}
  • of, relating to, or constituting mystery
  • exciting wonder, curiosity, or surprise while baffling efforts to comprehend or identify : mystifying
  • stirred by or attracted to the inexplicable

be mysterious

idiom
be mysterious \
  • to talk or behave in a way that makes other people feel that one must have a secret
Powered by Merriam-Webster