Recorded in several spellings as shown below, this is an English surname. It has two possible origins. Firstly it may be a byname applied to a cheerful person. If so then the origin is the Old English pre 7th century word "rot" meaning glad. Secondly it may be a metonymic occupational name for a musician, one who played the "rote", a medieval stringed instrument. The word "rote" is itself cognate with the Welsh "crwth", and describes a form of harp.