A thick mixture of water, fibers, and chemicals used in the pulp and paper industry. Slurry is the base stock from which paper and similar products are made on a paper forming machine. Water is first removed from the slurry with vacuum suction and press rollers until the product is at the desired thickness, and then dried in a (usually) natural gas powered oven to remove the rest of it. The fibers in the slurry hold the product together.
More generally, slurry is any granular or fibrous material mixed with water for the purpose of transferring it with a pump. Slurry is usually very abrasive and over time tends to wear down the pumps and machines used to process it.