Sentence:  There was no real sign of the river now , just a roiling , oily ribbon of liquid movement through muddy <WSD>waters</WSD> that reached everywhere . 
Meaning of the word marked with <WSD> tags:  binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent