rudder: [OE] Rudder comes from the same source as English row ‘use oars’ – prehistoric Germanic *rō- ‘steer’. Indeed it originally denoted an ‘oar used for steering’; the modern application to a fixed steering surface did not emerge until the 14th century. Its west Germanic ancestor *rōthra- also produced German ruder and Dutch roer. => row[rudder etymology, rudder origin, 英语词源]