Madison

A medieval English surname meaning "son of Maud" — Maud itself being a shortening of the Germanic Mathilda, "mighty in battle" — Madison spent most of its life attached to a founding father and a New York avenue. Then in 1984 a mermaid in a Tom Hanks movie adopted it as a joke, American parents took the joke seriously, and within a decade Madison had become one of the top girls' names in the country. It now sits at rank 46. Three syllables, brisk and confident, with a soft middle D. The rare name whose first-name-on-a-girl popularity is so thorough that its origin story has been completely rewritten.