in·sol·u·ble 
/ɪnˈsɑ:ljəbəl/ adjective
/ɪnˈsɑ:ljəbəl/ adjective 1 formal : not able to be solved or explained
▪ a seemingly insoluble [=(less formally) unsolvable] dilemma/mystery/problem 2 technical : not able to be dissolved in a liquid
▪ a substance insoluble in water — opposite soluble
▪ a seemingly insoluble [=(less formally) unsolvable] dilemma/mystery/problem
▪ a substance insoluble in water — opposite soluble
