has never been known(/seen) before; beyond (/without) example;unparalleled; unprecedented; without parallel;without precedent ❍ 新世界，就是要把人类社会推进到～的、无限美好的幸福境地。To build a new world is to raise human society to such a prosperous and happy state as has never been seen before. ❍ 第二年全县获得了空前未有的大丰收。In the following year an un precedented good harvest was reaped throughout the county.