A Venturi tube is a measuring instrument used in fluid dynamics to determine the velocity of a fluid through a pipe. There are several synonyms for Venturi tube, including nozzle, diffuser, constricted channel, and hydraulic dip tube. These all refer to a device that creates a constriction in a fluid path, forcing the fluid to increase in velocity to pass through. This increase in velocity results in a decrease in pressure, which can be used to measure the flow rate of the fluid. While Venturi tubes are commonly used in industries such as oil and gas, chemical manufacturing, and HVAC systems, the different synonyms for Venturi tubes demonstrate the variations in their design and applications across various industries.