Mysterious/mɪˈstɪriəs/ Definition 1 of 3Pro Tip 1/3Beyond Understanding Use 'mysterious' when something is beyond your comprehension, not just unknown. The way the magician vanished was simply mysterious. Pro Tip 2/3Evoke Curiosity Apply 'mysterious' to stir curiosity about phenomena or events that are not typical. He keeps to himself and his intentions remain mysterious. Pro Tip 3/3Supernatural Flair It's suitable for discussing subjects that might seem supernatural or otherworldly. They say the forest is home to mysterious creatures.