Of uncertain ultimate origin. This was the name of the mother of St Augustine, as transmitted to us by her famous son. She was a citizen of Carthage, so her name may well be of Phoenician origin, but in the early Middle Ages it was taken to be a derivative of Latin monere ‘to warn, counsel’, since it was as a result of her guidance that her son was converted to Christianity.
English and Welsh: patronymic from the Middle English personal name Jon(e) (see John). The surname is especially common in Wales and southern central England. In North America this name has absorbed various cognate and like-sounding surnames from other languages. (For forms, see Hanks and Hodges 1988).