Where does “chit” come from?

chit (Middle English) comes from Old English ċīþ, from Proto-Germanic kīþą, from Proto-Germanic kī-, from Proto-Indo-European gī- — to sing, to call, to shout.

Ancestry of “chit”, step by step

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

Every word from Proto-Indo-European gī- →

chit — Etymology, Origin & Word History | Etymology Explorer