unprecedented

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.

unorthodox, unorthodoxy, unpack, unpaid, unpalatable, unpalatably, unparalleled, unparliamentary, unpaved, unpick, unplaced, unplanned, unplayable, unpleasant, unpleasantly, unpleasantness, unplug, unpopular, unpopularity, unpractised, unprecedentedly, unpredictable, unprejudiced, unpremeditated, unprepossessing, unpretentious, unprincipled, unprintable, unproductive, unprofessional, unprofessionally, unprofitable, unpromising, unprompted, unpronounceable, unprovided, unprovoked, unpunished, unputdownable, unqualified,