fem. proper name, Old English Mildðryð, from milde "mild" (see mild) + ðryð "power, strength" (see Audrey). A popular name in the Middle Ages through fame of St. Mildred (obit c. 700), abbess, daughter of a Mercian king and a Kentish princess. Familiar forms include Milly, Midge. Among the 10 most popular names for girls born in the U.S. between 1903 and 1926, it hasn't been in the top 1,000 since 1983.