unprecedented [ʌnˈpresɪdentɪd]

以下由轻松背单词网站提供

adj.无前例的，新奇的

never having happened or existed in the past

The air crash caused an unprecedented number of deaths. 这次空难的死亡人数是空前的。
A flood of this sort is really unprecedented. 这样大的洪水真是十年九不遇。