He died in mysterious circumstances. See examples of mysterious used in a sentence. That which is mysterious, by being unknown or puzzling, excites curiosity or awe:
Pope Leo XIV (Robert Prevost) Complete Life Story
Inscrutable applies to that which is. Full of, characterized by, or involving mystery. This is reminiscent of the extraordinary relationship which amputees develop with their artificial replacements, revealing a whole inner mysterious.
How to use mysterious in a sentence.
The meaning of mysterious is of, relating to, or constituting mystery. Someone or something that is mysterious is strange and is not known about or understood.