From an Old English female personal name Mildþrӯð, derived from mild ‘gentle’ + þrӯð ‘strength’. This was the name of a 7th-century abbess, who had a less famous but equally saintly elder sister called Mildburh and a younger sister called Mildgӯð; all were daughters of a certain Queen Ermenburh. Their names illustrate clearly the Old English pattern of combining and recombining the same small group of name elements within a single family. This name was in fairly regular localized use until the early 18th century and it enjoyed a strong revival throughout England in the 19th century. Its use declined from the 1930s onwards.
English, Scottish, and northern Irish: distinguishing name (Middle English yunge, yonge ‘young’), for the younger of two bearers of the same personal name, usually distinguishing a younger brother or a son. In Middle English this name is often found with the Anglo-Norman French definite article, for example Robert le Yunge.