ballastyoudaoicibaDictYouDict[ballast 词源字典]
ballast: [16] Originally, ballast appears to have meant literally ‘bare load’ – that is, a load carried by a ship simply for the sake of its weight, and without any commercial value. English probably acquired it, via Low German, from a Scandinavian language; Old Swedish and Old Danish had not only ballast but also barlast, which appears to betray the word’s component parts: bar, related to English bare, and last ‘burden’ (Old English had hlæst ‘burden’, related to lade, which survived into the 20th century as a measure of weight for various commodities).
=> bare, lade[ballast etymology, ballast origin, 英语词源]
ballast (n.)youdaoicibaDictYouDict
"heavy material used to steady a ship," 1520s, from Middle English bar "bare" (see bare; in this case "mere") + last "a load, burden," or borrowed from identical terms in North Sea Germanic and Scandinavian (compare Old Danish barlast, 14c.). "Mere" because not carried for commercial purposes. Dutch balg-last "ballast," literally "belly-load," is a folk-etymology corruption.