Black hole

A dungeon or dark cell in a prison; a military lock-up or guardroom; -- now commonly with allusion to the cell (the Black Hole) in a fort at Calcutta, into which 146 English prisoners were thrust by the nabob Suraja Dowla on the night of June 20, 17656, and in which 123 of the prisoners died before morning from lack of air.

a region of space resulting from the collapse of a star; extremely high gravitational field