Where does “ātzintli” come from?

ātzintli (Classical Nahuatl) comes from Classical Nahuatl ātl, from Proto-Nahuan *aa-, from Proto-Uto-Aztecan pa — water.

Ancestry of “ātzintli”, step by step

StepLanguageWordMeaning
1Classical NahuatlātlAlternative spelling of atl; water
2Proto-Nahuan*aa-water
3Proto-Uto-Aztecanpawater
Every word from Proto-Uto-Aztecan pa →Every word from Proto-Nahuan *aa- →Every word from Classical Nahuatl ātl →