A gold placer dredger is a machine used to extract gold from riverbeds and streams. Synonyms for this term include: gold dredge, placer dredge, suction dredge, and mining dredge. A gold dredge is typically equipped with a suction hose and nozzle that are used to vacuum up sediment from the riverbed. The sediment is then run through a series of screens and sluice boxes to extract the gold. A placer dredge is typically smaller than a mining dredge, and is designed for use in shallow water. Synonyms for a gold placer dredger vary depending on the context of the conversation, but they all refer to machines used to extract gold from riverbeds.