That part of the sea out of sight of land.
A sea open to all nations, i.e. not a mare clausum.
A mass of small pieces of ice on the surface of a body of water.
A residual semi-solid material left from industrial, water treatment, or wastewater treatment processes.
Solids separated from suspension in a liquid.
sludge metal
A sediment of accumulated minerals in a steam boiler.
To slop or drip slowly.
To slump or slouch.