汉译英：境界（不是字典上边境的意思）

State 正解。

那位钢琴家所达到的完美境界不过是多年苦练得来的结果。
The perfection to which the pianist had attained was achieved only by years of hard work.

level
但是也要看具体的语境
有一些也可以翻译为

kind
或者是实意词就直接可以表达了