Where does “eichīn” come from?

eichīn (Middle High German) comes from Old High German eihhīn, from Proto-Germanic aikīnaz, from Proto-Germanic -īnaz, from Proto-Indo-European -iHnos, from Proto-Indo-European -no- — adjectival suffix.

Ancestry of “eichīn”, step by step

StepLanguageWordMeaning
1Old High Germaneihhīn—
2Proto-Germanicaikīnazoaken, made of oak
3Proto-Germanic-īnaz-en
4Proto-Indo-European-iHnosCreates adjectives of materials
5Proto-Indo-European-no-adjectival suffix
Every word from Proto-Indo-European -no- →Every word from Proto-Germanic -īnaz →Every word from Proto-Germanic aikīnaz →