faultless; flawless; irreproachable: impeccable manners.

What does a impeccable mean?

1 : free from fault or blame : flawless spoke impeccable French. 2 : not capable of sinning or liable to sin.

Does impeccable mean good or bad?

If you describe something such as someone's behaviour or appearance as impeccable, you are emphasizing that it is perfect and has no faults. She had impeccable taste in clothes. Her academic credentials are impeccable. He was impeccably polite.