/ven toor"ee/
a device for measuring the flow of a fluid, consisting of a tube with a short, narrow center section and widened, tapered ends, so that a fluid flowing through the center section at a higher velocity than through an end section creates a pressure differential that is a measure of the flow of the fluid.
Also, Venturi tube .
[ named after G. B. Venturi (1746-1822), Italian physicist whose work led to its invention ]