Where does “leivykkäin” come from?

leivykkäin (Ingrian) comes from Finnish -kkäin, from Finnish -käs, from Proto-Finnic -k'as, from Proto-Finnic -s, from Proto-Finno-Ugric -s.

Ancestry of “leivykkäin”, step by step

StepLanguageWordMeaning
1Finnish-kkäinFront vowel variant of -kkain
2Finnish-käsFront vowel variant of -kas
3Proto-Finnic-k'asForms adjectives from nouns, indicating a...
4Proto-Finnic-sForms nouns
5Proto-Finno-Ugric-s—
Every word from Proto-Finno-Ugric -s →Every word from Finnish -käs →Every word from Proto-Finnic -s →