derail (v.)youdaoicibaDictYouDict[derail 词源字典]
1850, in both transitive and intransitive senses, from French dérailler "to go off the rails," from de- (see de-) + railler (see rail (n.1)). In general use first in U.S. Related: Derailed; derailing. [derail etymology, derail origin, 英语词源]