My attempt at describing a black hole:

When a very big and very bright star runs out of stuff to burn, it can not stay big any longer and gets smaller and smaller, until it becomes nothing, but this nothing is just as heavy as before the star died. If you are close to it, you get sucked in and die. If light gets close to it, it dies, too. There is no escape. Since light can not escape, no one can see the place where the now dead star used to be. That is why this dead star is called black.

Words sorely missed: hole, curvature, density, vacuum, horizon.