In French, it’s called double v.

In latin, the letter V could mean our modern U or V; there was no distinction. In that light, double u makes sense.

I've always thought it was kinda poetic that it's double U in english because We is 2x U.

Old high German represented the Latin sound of V as UU. That's something called a digraph which was used more commonly to help understand what a word sounded like. In German W makes the sound of an English V (think Dracula saying: "I vant to suck your blood!") V makes a sound like English F. So when English inherited the W, it was called a double U, this differentiated the pronunciation from that of V and U in English. Double U is the only letter with 3 syllables to its name and the only one which has a name that's sound isn't a hint at pronouncing it. Even though many Germanic and Gallo-romance languages have Latin roots- their writing often incorporates certain symbols and transcribes certain sounds to letters in order to best fit the spoken sounds of that language.

Yay