A graviton pulse is a focused concentration of graviton particles.
In 2369, a Gamma Quadrant artifact brought to Deep Space Nine by Vash began to emit graviton pulses that disrupted station systems. The space station was dragged towards the Bajoran wormhole by the gravity created by the pulses, and received minor damage. (DS9: "Q-Less")
In 2375, a graviton pulse was used by a small Klingon fleet to disrupt the warp drives of several pursuing Jem'Hadar attack ships. (DS9: "Once More Unto the Breach")