Where does “Eachaidh” come from?

Eachaidh (Irish) comes from Old Irish ech, from Primitive Irish ᚓᚊᚐᚄ, from Proto-Celtic ekʷos, from Proto-Indo-European h₁éḱwos, from Proto-Indo-European h₁oh₁ḱu- — swift.

Ancestry of “Eachaidh”, step by step

StepLanguageWordMeaning
1Old Irishechhorse
2Primitive Irishᚓᚊᚐᚄhorse
3Proto-Celticekʷoshorse
4Proto-Indo-Europeanh₁éḱwosstallion, horse
5Proto-Indo-Europeanh₁oh₁ḱu-swift
Every word from Proto-Indo-European h₁oh₁ḱu- →Every word from Proto-Indo-European h₁éḱwos →Every word from Proto-Celtic ekʷos →