Where does “œsa” come from?

œsa (Old Norse) comes from Proto-Germanic jōsijaną, from Proto-Germanic jōsiz, from Proto-Indo-European yes- — to foam; to boil.

Ancestry of “œsa”, step by step

StepLanguageWordMeaning
1Proto-Germanicjōsijanąto stir up, excite
2Proto-Germanicjōsiztumultuous
3Proto-Indo-Europeanyes-to foam; to boil
Every word from Proto-Indo-European yes- →Every word from Proto-Germanic jōsiz →Every word from Proto-Germanic jōsijaną →