herdsman (n.)youdaoicibaDictYouDict[herdsman 词源字典]
Old English heordman, but the word was not common until herd (Old English hierde) in sense "keeper of domestic animals which go in herds" fell from use (see shepherd). See herd (n.) + man (n.). Intrusive -s- appeared early 15c., on model of craftsman, etc.[herdsman etymology, herdsman origin, 英语词源]