Billi Is A Girl’s Name Of Germanic Origin. It’s A Shortened Form Of The Germanic Name Wilhelm, Translated Into English As William. The Name Combines The Elements wil (will, Desire) With helm (helmet, Protection) To Mean “determined Protector.” William Is Often Shortened To Billy, Traditionally A Boy’s Name, But The Spellings Billi And Billie Have Become Popular For Girls. This Is Due To The Iconic Jazz Singer Billie Holiday, And More Recently, Singer-songwriter Billie Eilish. Another Famous Bearer Is Actress Billie Lourd, Daughter Of Carrie Fisher. Dropping The “e” Could Make This Name An Even More Distinctive Choice For Baby.