Where does “-ein” come from?

-ein (Old French) comes from Old French halt, from Latin altus, from Proto-Italic altos, from Proto-Indo-European h₂eltós, from Proto-Indo-European h₂él- — to grow, nourish.

Ancestry of “-ein”, step by step

StepLanguageWordMeaning
1Old Frenchhalthigh; elevated; loud; loudly
2Latinaltushigh, tall; deep; profound
3Proto-Italicaltos—
4Proto-Indo-Europeanh₂eltós—
5Proto-Indo-Europeanh₂él-to grow, nourish
Every word from Proto-Indo-European h₂él- →Every word from Proto-Indo-European h₂eltós →Every word from Proto-Italic altos →