noun
: a wave in which the propagated disturbance is a variation of temperature and of which the velocity is ordinarily very small except in the case of liquid helium II where the wave speed approaches that of sound — compare second sound
noun
: a wave in which the propagated disturbance is a variation of temperature and of which the velocity is ordinarily very small except in the case of liquid helium II where the wave speed approaches that of sound — compare second sound
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012