The adjective impeccable means something that has a perfect appearance, and has no faults.
Synonyms are unblemished, precise, immaculate, or exquisite.
The word origins from Middle French (15th century) impeccable meaning “not capable of sin” or directly from Late Latin impeccabilis meaning “not liable to sin”. It is derived out of its assimilated form of in– meaning “not, opposite of” plus the Latin verb peccare meaning “to sin”.
He takes pride of his impeccable reputation.
Your timing was impeccable! You just arrived when they were giving free gifts for the festival.
The employer was impressed by his impeccable credentials.