sudd

A floating mass of vegetation that obstructs navigation in tropical rivers, found chiefly in upper portions of the Nile River.

An impenetrable mass of floating water-plants interlaced with trunks of trees and decayed vegetable matter, forming floating islands in the White Nile.

See sadd.

A tangled mass of floating vegetal matter obstructing navigation.

A floating mass of plant matter, such as reeds, which obstructs boat passage on the Nile