Where does “Guyenne” come from?

Guyenne (French) comes from Old French Guyenne, from Latin Aquitania, from Latin aqua, from Proto-Italic akʷā, from Proto-Indo-European h₂ekʷeh₂ — water, flowing water.

Ancestry of “Guyenne”, step by step

StepLanguageWordMeaning
1Old FrenchGuyenne—
2LatinAquitaniaAquitaine
3Latinaquawater
4Proto-Italicakʷāwater
5Proto-Indo-Europeanh₂ekʷeh₂water, flowing water
Every word from Proto-Indo-European h₂ekʷeh₂ →Every word from Proto-Italic akʷā →Every word from Latin aqua →