1. impossible to understand or interpret; mysterious

Examples

• The professor’s inscrutable expression made it impossible to tell if he was pleased with our presentation.
• Ancient hieroglyphs remained inscrutable to scholars for centuries.
• Her inscrutable smile left everyone wondering what she was really thinking.
• The CEO’s inscrutable decision to close the profitable division surprised investors.
• The cat’s inscrutable gaze seemed to hold secrets we could never understand.
• His inscrutable behavior at the meeting left his colleagues confused about his intentions.