Where does “nước Bắc” come from?

nước Bắc (Vietnamese) comes from Vietnamese nước, from Proto-Vietic ɗaːk, from Proto-Mon-Khmer ɗaak — water; liquid; The sense of "river, stream" that...

Ancestry of “nước Bắc”, step by step

nước Bắc traces back through two separate lines of ancestry.

via Vietnamese nước

Step	Language	Word	Meaning
1	Vietnamese	nước	water; liquid; fluid; the liquid part of a broth
2	Proto-Vietic	ɗaːk	water, liquid
3	Proto-Mon-Khmer	ɗaak	water; liquid; The sense of "river, stream" that...

via Vietnamese Bắc

Step	Language	Word	Meaning
1	Vietnamese	Bắc	North
2	Middle Chinese	北	—

Every word from Proto-Mon-Khmer ɗaak →Every word from Proto-Vietic ɗaːk →Every word from Vietnamese nước →