Where does “odieus” come from?

odieus (Old French) comes from Latin odiōsus, from Latin odium, from Proto-Indo-European h₃ed- — to smell, stink; to hate; to bite.

Ancestry of “odieus”, step by step

Step	Language	Word	Meaning
1	Latin	odiōsus	—
2	Latin	odium	hatred, ill-will, aversion, dislike, disgust,...
3	Proto-Indo-European	h₃ed-	to smell, stink; to hate; to bite

odieus — Etymology, Origin & Word History | Etymology Explorer