Where does “partialitas” come from?

partialitas (Latin) comes from Latin pars, from Proto-Indo-European per-, from Proto-Indo-European pr̥tós — passed , crossed.

Ancestry of “partialitas”, step by step

Step	Language	Word	Meaning
1	Latin	pars	part, side, piece, share; some; faction
2	Proto-Indo-European	per-	before, in front; first; to go through
3	Proto-Indo-European	pr̥tós	passed , crossed

partialitas — Etymology, Origin & Word History | Etymology Explorer