counterpart (n.)youdaoicibaDictYouDict[counterpart 词源字典]
mid-15c., originally countre part "duplicate of a legal document," from Middle French contrepartie, from contre "facing, opposite" (see contra-) + partie "copy of a person or thing," originally fem. past participle of partir "to divide" (see party (n.)).[counterpart etymology, counterpart origin, 英语词源]