Millie

Millie is an English diminutive form that arose primarily from Mildred, an Old English name composed of the elements milde, meaning gentle or mild, and þryð, meaning strength or power. It has also functioned as a short form of Millicent, a name of Germanic origin meaning strong in work. The name gained widespread popular use in the nineteenth century and has seen a notable revival in the twenty-first century across English-speaking countries. Related forms include Milly, Mildred, and Millicent.