1. a thin paste produced by mixing an insoluble substance, such as cement or clay, with enough water or other liquid to allow the mixture to flow viscously. 2. to prepare such a paste. Thus, slurrying. 3. Oil & Gas.. a suspension of pulverized solid material in water or oil, pumped or poured into pipelines. 4. a thin, free-flowing mixture of water and cement pumped into an oil well through the drill pipe, to support the casing and seal the wellbore. 5. see coal slurry.