Where does “Aquino” come from?

Aquino (Italian) comes from Latin Aquinum, from Latin aqua, from Proto-Italic akʷā, from Proto-Indo-European h₂ekʷeh₂ — water, flowing water.

Ancestry of “Aquino”, step by step

StepLanguageWordMeaning
1LatinAquinumOne of the most important cities of the Volsci, situated between Fabrateria and Casinum, now Aquino
2Latinaquawater
3Proto-Italicakʷāwater
4Proto-Indo-Europeanh₂ekʷeh₂water, flowing water
Every word from Proto-Indo-European h₂ekʷeh₂ →Every word from Proto-Italic akʷā →Every word from Latin aqua →