noun
: an instrument for determining the depth of a body of water or of an object below the surface by measuring the interval of time between the emission of a sound signal and the return of its echo from the bottom or the object
noun
: an instrument for determining the depth of a body of water or of an object below the surface by measuring the interval of time between the emission of a sound signal and the return of its echo from the bottom or the object
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012