noun
: a pulse (as an electromagnetic pulse) that is the resultant of a number of wave trains of differing wavelengths and speed and has a definite group velocity
noun
: a pulse (as an electromagnetic pulse) that is the resultant of a number of wave trains of differing wavelengths and speed and has a definite group velocity
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012