Millie

English

Diminutive of Mildred, Millicent and other names containing the same sound, meaning "From the Old English name Mildþryð meaning "gentle strength", derived from the elements milde "gentle" and þryð "strength". Saint Mildred was a 7th-century abbess, the daughter of the Kentish princess Saint Ermenburga. After the Norman conquest this name became rare, but it was revived in the 19th century."