/ Qn5presIdentId; Qn`prZsE9dZntId/ adj without precedent; never having happened, been done or been known before 无前例的; 前所未有的; 空前的: unprecedented levels of unemployment 失业率达到的前所未有的严重程度 * a situation unprecedented in the history of the school 该校自有校史以来未曾出现过的情况.