Where does “orientalis” come from?

orientalis (Latin) comes from Latin oriēns, from Latin orior, from Proto-Indo-European h₃ér-.

Ancestry of “orientalis”, step by step

Step	Language	Word	Meaning
1	Latin	oriēns	—
2	Latin	orior	I rise, get up; I appear, become visible; I am...
3	Proto-Indo-European	h₃ér-	—

orientalis — Etymology, Origin & Word History | Etymology Explorer