adj.無懈可擊的；無瑕疵的

Your English is impeccable! 你的英語十分好！

He was proud of his impeccable pedigree. 他為他出身于名門望族而驕傲。

He was proud of his impeccable good manners. 他為自己無可挑剔的端莊舉止而感到自豪。

From this we can see her impeccable moral integrity. 從這件事上，我們看到了她白璧無暇的美好心靈。