barmy (adj.)youdaoicibaDictYouDict[barmy 词源字典]
1530s, "frothing, covered with barm;" see barm + -y (2). Figurative sense of "excited, flighty, bubbling with excitement" is from c. 1600. Meaning "foolish" (1892) is probably an alteration of balmy.[barmy etymology, barmy origin, 英语词源]