errant (adj.)youdaoicibaDictYouDict[errant 词源字典]
mid-14c., "travelling, roving," from Anglo-French erraunt, from two Old French words that were confused even before they reached English: 1. Old French errant, present participle of errer "to travel or wander," from Late Latin iterare, from Latin iter "journey, way," from root of ire "to go" (see ion); 2. Old French errant, past participle of errer (see err). The senses fused in English 14c., but much of the sense of the latter since has gone with arrant.[errant etymology, errant origin, 英语词源]