This kanji is made of two parts. On the left is the ‘word’ radical, which originally represented a sacred oath made before God—one so absolute that breaking it meant punishment by the sword. On the right is an element representing a crossroads with branching paths, making it unclear which way to go. Combined, this kanji came to represent asking with words what something is or where to go, giving it the meaning of ‘riddle’ or ‘mystery.