13世纪早期,“通过不诚实手段获得或保留他人的钱财或个人物品;” 13世纪中期,“习惯性偷窃;” 来自古英语 þeofð (West Saxon þiefð) “盗窃。” 这被重建为源自原始日耳曼语 *theubitho (古弗里西亚语 thiufthe, 古诺尔斯语 þyfð 的来源),来自 *theubaz “小偷”(参见 thief)+ 抽象构成后缀 *-itha,与拉丁语 -itatem 同源(参见 -th (2))。
在中古英语中,有时扩展到高利贷或收取利息。中古英语中还有 theftly “偷偷地”(14世纪晚期); theftuous “盗贼的”(约1500年)。
From the usurer to his sons, there a current swiftly runs ;
From the sons to queans in chief, from the gallant to the thief ;
From the thief unto his host, from the host to husband-men ;
From the country to the court ; and so it comes to us again.
[Thieves' Song from "The Widow," c. 1616]