impeccable

adjective
1

Perfect, without faults, flaws or errors.

"He grew up in Norway, but he writes impeccable English."

2

Incapable of wrongdoing or sin; immaculate.

"It was easy for James V to imprison Lady Glamis, but actually convicting her was far more difficult; her character was impeccable and she was highly respected by all who knew her."

Source: https://en.wiktionary.org/wiki/impeccable

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