The word impeccable has been used in English since the 16th century. It derives from the Latin word impeccabilis, a combination of the Latin prefix in-, meaning “not,” and the verb peccare, meaning “to sin.” Peccare has other descendants in English. There is peccadillo, meaning “a slight offense,” and peccant, meaning “guilty of a moral offense” or simply “faulty.” There is also peccavi, which comes from Latin, where it literally means “I have sinned”; in English the word functions as a noun meaning “an acknowledgement of sin.”