Where does “adverbium” come from?

adverbium (Latin) comes from Latin Ad, from Latin illic, from Latin ille, from Latin olle, from Proto-Italic *olnos — that.

adverbium (Latin): adverb

Definitions

adverbium traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	Latin	Ad	toward, to
2	Latin	illic	he, she, it, yonder, that, overthere; in that...
3	Latin	ille	that; those; "; demonstrative pronoun "; that...
4	Latin	olle	Archaic form of ille
5	Proto-Italic	*olnos	that

Step	Language	Word	Meaning
1	Latin	verbum	word; proverb, saying; verb
2	Ancient Greek	λόγος	That which is said: word, sentence, speech,...
3	Ancient Greek	λέγω	I put in order, arrange, gather; I choose, count,...
4	Proto-Indo-European	leǵ-	to gather, collect, with derivatives meaning to...