Underriddle is a rarely used word, and its spelling may cause confusion. It is pronounced /ˈʌndərɪd(ə)l/, with the stress on the first syllable. The "underr" portion comes from the prefix "under-", which denotes beneath or lower in position. The second part, "riddle," means a puzzle or a mystery. When combined, "underriddle" means a mystery or puzzle that is hidden or obscure. Although it is not commonly used, its unique spelling and meaning make it a fascinating word.