Where does “अथर्ववेद” come from?

अथर्ववेद (Sanskrit) comes from Sanskrit वेद, from Proto-Indo-European wóyde, from Proto-Indo-European weyd- — to see.

Ancestry of “अथर्ववेद”, step by step

Step	Language	Word	Meaning
1	Sanskrit	वेद	knowledge, true or sacred knowledge or lore,...
2	Proto-Indo-European	wóyde	to have seen, to know
3	Proto-Indo-European	weyd-	to see

अथर्ववेद — Etymology, Origin & Word History | Etymology Explorer