See black hole in Webster's New World College Dictionary
a celestial object or dark region in space, perhaps formed by the collapse of a large star, with such a great mass that its gravitational field will not let even light escape
an emptiness or void
anything thought of as endlessly devouring resources, funds, etc.
a small dungeon at Calcutta: it was once believed that over 100 Europeans were confined there one night in 1756 by their Indian captors and died from heat and lack of air
any dungeon
See black hole in American Heritage Dictionary 4
noun
An area of space-time with a gravitational field so intense that its escape velocity is equal to or exceeds the speed of light.
A great void; an abyss: The government created a bureaucratic black hole that swallows up individual initiative.