unpleasantness (n.)youdaoicibaDictYouDict[unpleasantness 词源字典]
1540s, "state or quality of being unpleasant," from unpleasant + -ness. By 1835 as "a slight quarrel, a minor misunderstanding." The late unpleasantness as a humorously polite Southern description of the American Civil War is attested from 1868.[unpleasantness etymology, unpleasantness origin, 英语词源]