Where does “Chordata” come from?

Chordata (Translingual) comes from Latin chorda, from Ancient Greek χορδή, from Proto-Indo-European *ǵʰerH-.

Ancestry of “Chordata”, step by step

Step	Language	Word	Meaning
1	Latin	chorda	cord, string; tripe, intestine; catgut
2	Ancient Greek	χορδή	guts, intestines; string made of gut; string,...
3	Proto-Indo-European	*ǵʰerH-	—

Chordata — Etymology, Origin & Word History | Etymology Explorer