Where does “half-” come from?

half- (Middle English) comes from Old English healf-, from Old English healf, from Proto-Germanic *halb, from Proto-Germanic halbaz, from Proto-Indo-European (s)kelH-, from Proto-Indo-European (s)kel- — to bend, crook; bent, crooked; leg, heel, knee,...

Ancestry of “half-”, step by step

Step	Language	Word	Meaning
1	Old English	healf-	—
2	Old English	healf	side; half; partly
3	Proto-Germanic	*halb	—
4	Proto-Germanic	halbaz	half
5	Proto-Indo-European	(s)kelH-	to cut; to split, to separate
6	Proto-Indo-European	(s)kel-	to bend, crook; bent, crooked; leg, heel, knee,...

Words derived from “half-”

halftone
half-cousin
half-hourly
half-sibling
half-island
half-blood
half-bound
half-bred
half-hunter
half-baked
half-expect
half-hardy
half-sib
half-brother
half-pint
half-embrace
half-dozen
half-jacket
half-
half-ray
half-angel
half-demon
half-dollar
half-witch

Every word from Proto-Indo-European (s)kel- →