Where does “πρίστις” come from?

πρίστις (Ancient Greek) comes from Ancient Greek -τις, from Proto-Indo-European -tis — Derives abstract/action nouns from verb roots.

Ancestry of “πρίστις”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	-τις	Earlier form of -σις , retained after dentals δ,...
2	Proto-Indo-European	-tis	Derives abstract/action nouns from verb roots

πρίστις — Etymology, Origin & Word History | Etymology Explorer