immaculateyoudaoicibaDictYouDict[immaculate 词源字典]
immaculate: [15] A macula in Latin was a ‘spot’ or ‘stain’ (as well as a ‘hole in a net’, which gave English the mail of chain mail). Hence anything that was immaculātus (an adjective formed with the negative prefix in-) was ‘spotless’ – ‘perfect’.
=> chainmail[immaculate etymology, immaculate origin, 英语词源]