Where does “nonalterable” come from?

nonalterable (English) comes from English alterable, from English alter, from Old French alterer, from Medieval Latin alterare, from Latin alter, from Proto-Indo-European h₂élteros, from Proto-Indo-European h₂el- — to grow, nourish; beyond, other; to wander, roam.

Ancestry of “nonalterable”, step by step

nonalterable traces back through two separate lines of ancestry.

via English alterable

StepLanguageWordMeaning
1EnglishalterableCapable of being changed, changeable, mutable;...
2EnglishalterTo change the form or structure of; To become...
3Old Frenchalterer
4Medieval Latinalterareto make other; present active infinitive of...
5Latinalterthe other, the second; the one...the other
6Proto-Indo-Europeanh₂élterosother , second
7Proto-Indo-Europeanh₂el-to grow, nourish; beyond, other; to wander, roam

via English non

StepLanguageWordMeaning
1EnglishnonObsolete form of none
2Frenchnonno; not; a no, a negative response
3Old Frenchnonno; not; Alternative form of nom
4Latinnōnnot
5Old Latinnoenum
6Proto-Indo-Europeanóynosone; single
Every word from Proto-Indo-European h₂el-