Where does “kithō” come from?

kithō (Frankish) comes from Proto-Germanic kīþą, from Proto-Germanic kī-, from Proto-Indo-European gī- — to sing, to call, to shout.

Ancestry of “kithō”, step by step

Step	Language	Word	Meaning
1	Proto-Germanic	kīþą	seed, germ; seedling, shoot, sprout
2	Proto-Germanic	kī-	to split open, germinate, sprout
3	Proto-Indo-European	gī-	to sing, to call, to shout

kithō — Etymology, Origin & Word History | Etymology Explorer