"Hurrah"
"Hourra!"
"Urrà!"
Etc.

They seem to have an unclear origin: https://en.wikipedia.org/wiki/Huzzah

I agree most with the Turkish origin, btw.

In French, Au rat means: "to the mouse / rat".

It may mean something like: "To the mouse [you go]!" But that's just my intuition.

Rat is also a familiar term to describe your beloved ones (e.g. mes rats = my pets = the mouths I must feed).