2ADJ-GRADED [usually ADJ n](质量、数量、规模)很高的,很大的 If you describe something as unprecedented, you are emphasizing that it is very great in quality, amount, or scale. (质量、数量、规模)很高的,很大的 [emphasis]
Each home boasts an unprecedented level of quality throughout.
每家的质量都堪称一流。
The scheme has been hailed as an unprecedented success.