S: (n) seiche (a wave on the surface of a lake or landlocked bay; caused by atmospheric or seismic disturbances)
S: (n) standing wave, stationary wave (a wave (as a sound wave in a chamber or an electromagnetic wave in a transmission line) in which the ratio of its instantaneous amplitude at one point to that at any other point does not vary with time)
S: (n) pulsation, pulsing, pulse, impulse ((electronics) a sharp transient wave in the normal electrical state (or a series of such transients)) "the pulsations seemed to be coming from a star"