Wiktionary
n. The stage in the evolution of a star in which the pressure of the star is insufficient to maintain it at a stable size, and its material falls inward under its own gravitational attraction, eventually forming a black hole or a neutron star, and sometimes accompanied by a supernova explosion.
WordNet
n. the implosion of a star resulting from its own gravity; the result is a smaller and denser celestial object
Wikipedia
Gravitational collapse is the contraction of an astronomical object due to the influence of its own gravity, which tends to draw matter inward toward the center of mass. Gravitational collapse is a fundamental mechanism for structure formation in the universe. Over time an initial relatively smooth distribution of matter will collapse to form pockets of higher density, typically creating a hierarchy of condensed structures such as clusters of galaxies, stellar groups, stars and planets.
A star is born through the gradual gravitational collapse of a cloud of interstellar matter. The compression caused by the collapse raises the temperature until thermonuclear fusion occurs at the center of the star, at which point the collapse gradually comes to a halt as the outward thermal pressure balances the gravitational forces. The star then exists in a state of dynamic equilibrium. Once all its energy sources are exhausted, a star will again collapse until it reaches a new equilibrium state.
Usage examples of "gravitational collapse".
During the gravitational collapse of a star to form a black hole, the movements would be much more rapid, so the rate at which energy is carried away would be much higher.
The gravitational collapse of the prestellar cloud has been halted.
Recall that neutron stars are incredibly dense, formed when a larger star undergoes gravitational collapse.
You'd need six or seven billion solar masses undergoing gravitational collapse to release that much energy.
Indeed, the scenario of gravitational collapse makes it even more plausible: you just have to start with a big enough concentration of matter, such as a neutron star or the centre of a galaxy.
Those shards were the relics of a catastrophe four billion years earlier, when a toroidal region of space-time had suffered gravitational collapse and spewed high-mass elements toward the Sun.
Because Dis was large enough to generate a fair amount of thermal radiation through gravitational collapse, the Disward side of Caern was desert, while the antipodes were ice-locked tundra, glacier, and solid-frozen ocean.
I recalled old predictions that an infinite universe would be prone to disastrous gravitational collapse-it was another reason why our own cosmos could not, logically, be infinite.
A full set of rules is so massively complicated that the only time they were all bound together in a single volume, they underwent gravitational collapse and became a Black Hole.
It was, of course, an unconscious enemy, animated but without any kind of life, a machine powered by gravitational collapse, incapable of animosity.
Had it required nothing less than gravitational collapse to bring Marlene to his arms?