SOUNDING

n. 1 a the action or process of measuring the depth of water, now usu. by means of echo. b an instance of this (took a sounding). 2 (in pl.) a a region close to the shore of the right depth for sounding. b Naut. measurements taken by sounding. c cautious investigation (made soundings as to his suitability). 3 a the determination of any physical property at a depth in the sea or at a height in the atmosphere. b an instance of this. øsounding-balloon a balloon used to obtain information about the upper atmosphere. sounding-line a line used in sounding the depth of water. sounding-rod a rod used in finding the depth of water in a ship's hold (see SOUND(3)).