We now hear “impeccable” or “impeccably” in terms of good manners, discerning taste or fine tailoring and grooming. It has come to mean ‘fastidious or of unquestionable propriety,’ but it comes from late Latin impeccābil-is, from the negative prefix im- + peccāre ‘to sin.’ Originally it meant ‘not capable of or liable to sin; exempt from the possibility of sinning or doing wrong.’
“Though she never sinned, yet she was not so impeccable, but she might have sinned.” Hugh Latimer · Sermons and remains 1555
“Its credentials are about as impeccable as you can find in the peccable atmosphere of Hollywood.” New York Times, March 13, 1992
“Peccadillo” meaning, ‘a minor fault or sin, a trivial offense,’ also derives from the Latin peccāre.