The nile is a major north-flowing river in northeastern africa. it flows into the mediterranean sea. the nile is the longest river in africa and has historically been considered the longest river in the world, though this has been contested by research suggesting that the amazon river is slightly longer. the nile's modern name comes from the nelios, the greek word for river valley. but the ancient egyptians called it ar or aur,meaning black, a reference to the rich, dark sediment that the nile's waters carried from the horn of africa northward and deposited in egypt as the river flooded its banks each year in late summer.