Where does “patiēns” come from?

patiēns (Latin) comes from Latin patior, from Proto-Indo-European peh₁- — to hate, hurt.

Ancestry of “patiēns”, step by step

Step	Language	Word	Meaning
1	Latin	patior	I suffer, endure; I allow, acquiesce, permit,...
2	Proto-Indo-European	peh₁-	to hate, hurt

patiēns — Etymology, Origin & Word History | Etymology Explorer