Having an intriguing quality or being difficult to understand

Something that is secret or unknown

कुछ ऐसा जो गुप्त या अज्ञात हो

English Usage: The book is filled with mysterious symbols that no one can decipher.

Hindi Usage: किताब में रहस्यमय प्रतीकों से भरी है जिन्हें कोई भी समझ नहीं सकता।