Where does “Vietnamca” come from?

Vietnamca (Turkish) comes from Turkish Vietnam, from Vietnamese Việt Nam, from Vietnamese Nam Việt, from Middle Chinese 南.

Ancestry of “Vietnamca”, step by step

Step	Language	Word	Meaning
1	Turkish	Vietnam	Vietnam
2	Vietnamese	Việt Nam	Vietnamese
3	Vietnamese	Nam Việt	—
4	Middle Chinese	南	—

Vietnamca — Etymology, Origin & Word History | Etymology Explorer