A Dragon Break is when the linearity of time breaks down. In such a state, you dont have an orderly sequence of events, as time normally is (leaving relativity aside, thats IRL
) - inmstead, you have a state where really everything is possible and dozens of different things happen at the same time. As "Where were you etc." said, Cyrodiil at the same time became an egg, reached out to the stars and whatnot.
The first of the four ages we know about in TES, the Dawn Age, was such a time as well, which is why Dragon Breaks, or at least the Great Dragon Break, are also called Middle Dawns. In that mythical beginning of Mundus and Nirn, there was no linear time, no historical causality, and hundreds of differnet things happened at the same time, which is why there cant be any true historic study of the time. Then the gods made their convent at Adamantium Tower and left Nirn, and time became linear. (of course, weve recently learned that in fact the Dawn Age is the last age of the last kalpa, instead of the first age, but the principle remains the same - time was non-linear until the Gods Convention).
THE Great Dragon Break was in the First Era, caused by a sect called the Maruhki Selectives. They wanted to divide Auriel (as the time god is called among the Elves) from Akatosh (as its called among Men), that is, they wanted to remove the "elven parts" of Akatosh. Common intepretation of what they actually did is mantling the Eight Divines, that is, becoming those gods. (Which reminds me I wanted to write something about that...)
More minor Dragon Breaks we know of are the ascendancy of the Tribunal (upon reaching godhood, there have always been the Tribunal Gods) and the Warp in the West (where people meddled with divine Numidium). So, yes, the presence of the divine harming time linearity, that seems to fit.