Where does “*peheikkö” come from?

*peheikkö (Finnish) comes from Finnish -ikko, from Proto-Finnic -ikko, from Proto-Finnic -i- — Plural number marker in other cases than the nominative (and optionally the genitive).

Ancestry of “*peheikkö”, step by step

StepLanguageWordMeaning
1Finnish-ikkoForms nouns for groups of a particular number,...
2Proto-Finnic-ikkoForms nouns indicating a group of things
3Proto-Finnic-i-Plural number marker in other cases than the nominative (and optionally the genitive)
Every word from Proto-Finnic -i- →Every word from Finnish -ikko →Every word from Proto-Finnic -ikko →