If a problem or difficulty is ~, no satisfactory solution has been found to it. (FORMAL)
The murder remains ~.
...~ issues.
ADJ: v-link ADJ, ADJ n, ADJ after v
If a problem or difficulty is ~, no satisfactory solution has been found to it. (FORMAL)
The murder remains ~.
...~ issues.
ADJ: v-link ADJ, ADJ n, ADJ after v
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012