Where does “achever” come from?

achever (Old French) comes from Latin accapāre, from Latin Ad, from Latin illic, from Latin ille, from Latin olle, from Proto-Italic *olnos — that.

Ancestry of “achever”, step by step

achever traces back through two separate lines of ancestry.

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

Step	Language	Word	Meaning
1	Vulgar Latin	accapare	present active infinitive of *accapō;...
2	Latin	ad	toward, to; up to; near, by, close by, at, to