Where does “odious” come from?

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

Ancestry of “odious”, step by step

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

Words derived from “odious”

odious
odiously
odiousness
unodious

Every word from Proto-Indo-European h₃ed- →

odious — Etymology, Origin & Word History | Etymology Explorer