Impeccancy is a rather obscure term, often replaced with more commonly understood synonyms such as perfection or flawlessness. Other synonyms for impeccancy include faultlessness, purity, precision, exactitude, excellence, and accuracy. These words all convey a sense of being faultless or without mistake, which is the essence of impeccancy. When it comes to describing a person's character, synonyms such as morality, integrity, and righteousness might be more appropriate, while in the realm of business or work, efficiency or productivity might be used. Whatever the context, the synonyms for impeccancy all share the notion of being perfect or without flaw.