mysterious
/mɪˈstɪriəs/
adjective
- Difficult or impossible to understand, explain, or identify; strange and unknown.
- A mysterious package arrived at the door with no return address.
- The old house had a mysterious atmosphere that made everyone feel uneasy.
- Scientists are trying to solve the mysterious disappearance of the ancient civilization.
- Deliberately secretive or enigmatic in behavior or appearance.
- The detective was known for his mysterious manner, never revealing his next move.
- He wore a mysterious expression that made his friends wonder what he was thinking.
- She gave him a mysterious smile and walked away without saying a word.