Imagine you're trying to get the last drop of ketchup out of the bottle. That violent, desperate shaking? 'Yan ang pag-ug-og. It's what happens to you inside a jeepney running over a pothole-filled road. It's a more intense, more aggressive version of "yugyog" or "alog." Not a gentle rock, but a full-on, brain-rattling shake. The verb form is 'ug-ugin'.