Merriam-Webster Collegiate Dictionary - pitot tube

 noun  Usage: often capitalized P  Etymology: French (tube de) Pitot, from Henri Pitot died 1771 French physicist  Date: circa 1859  1. a device that consists of a tube having a short right-angled bend which is placed vertically in a moving body of fluid (as air) with the mouth of the bent part directed upstream and that is used with a manometer to measure the velocity of fluid flow  2. pitot-static tube