Ossiriand

Ossiriand (S. "Land of the Seven Rivers", also "Ossír", Os. "Ossîrin" ; Q. "Otssiriande") was the land between the rivers Ascar and Adurant, including the rivers Thalos, Legolin, Duilwen and Brithor. The seventh river was the Gelion herself. Even riven by the Gulf of Lune in the Second Age, this name was still used as an occasional synonym for Lindon.