Where does “sîsîpisis” come from?

sîsîpisis (Plains Cree) comes from Plains Cree -is, from Proto-Algonquian *-ehs.

Ancestry of “sîsîpisis”, step by step

StepLanguageWordMeaning
1Plains Cree-isUsed to form diminutives: -ie
2Proto-Algonquian*-ehs
Every word from Proto-Algonquian *-ehsEvery word from Plains Cree -is