Where does “gansch” come from?

gansch (Middle Dutch) comes from Middle High German ganz, from Old High German ganz, from Proto-West Germanic gant, from Proto-Indo-European gʷʰen-, from Proto-Indo-European bʰon-.

Ancestry of “gansch”, step by step

Step	Language	Word	Meaning
1	Middle High German	ganz	—
2	Old High German	ganz	whole, entire, sound, complete; whole, sound,...
3	Proto-West Germanic	gant	whole, healthy; all, complete
4	Proto-Indo-European	gʷʰen-	to strike, slay, kill
5	Proto-Indo-European	bʰon-	—

Every word from Proto-Indo-European bʰon- →

gansch — Etymology, Origin & Word History | Etymology Explorer