impeccable

形容词 impeccable:

1. without fault or error
   同义词：faultless, immaculate
2. not capable of sin

1. He was proud of his impeccable pedigree.
   他为他出身于名门望族而骄傲。
2. Your English is impeccable!
   你的英语十分好！

im.pec.ca.ble

adj.（形容词）
Having no flaws; perfect.See Synonyms at perfect
无瑕疵的；完美的参见 perfect
Incapable of sin or wrongdoing.
不犯罪的；不做坏事的

来源：
Latin impecc3bilis
拉丁语 impecc3bilis
in- [not] * see in-
in- [不] *参见 in-
pecc3re [to sin] * see ped-
pecc3re [犯罪] *参见 ped-

【引伸】
impec.cabil.ity
n.（名词）
impec.cably
adv.（副词）