Where does “ἀλέθω” come from?

ἀλέθω (Byzantine Greek) comes from Ancient Greek ἀλέω, from Proto-Indo-European h₂elh₁- — to grind; heat; ground.

Ancestry of “ἀλέθω”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ἀλέω	To grind, bruise, pound, mill; second-person...
2	Proto-Indo-European	h₂elh₁-	to grind; heat; ground

ἀλέθω — Etymology, Origin & Word History | Etymology Explorer