Hanoin.

Hanoicity in northern Vietnam, from Vietnamese Hà Nôi, literally "River Inside," from hà "river" + nôi "inside." So called in reference to its situation in a bend of the Red River. Known 18c. as Dong Kinh "Eastern Capital," which was corrupted by Europeans into Tonkin, Tonquin, and that name was used in the French colonial period to refer to the entire region and extended to the gulf to the east.