a pipe, chamber, or compartment having closed sides and bottom except for a comparatively small inlet, or inlets, connected to the main body of water —note 1. a stilling well is used for attenuating waves or surges while permitting the water level within the well to rise and fall with major fluctuations of the main body —note 2. a stilling well is used with water-measuring devices to improve accuracy of measurement This definition last updated 10/14/2008