(Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment; "Hurl'd headlong...To bottomless perdition, there to dwell"- John Milton; "a demon from the depths of the pit"
a cause of difficulty and suffering; "war is hell"; "go to blazes"
any place of pain and turmoil; "the hell of battle"; "the inferno of the engine room"; "when you're alone Christmas is the pits";
a method of surveying; the area is divided into triangles and the length of one side and its angles with the other two are measured, then the lengths of the other sides can be calculated
a trigonometric method of determining the position of a fixed point from the angles to it from two fixed points a known distance apart; useful in navigation
an unstable construction with playing cards; "he built three levels of his cardcastle before it collapsed"
a speculative scheme that depends on unstable factors that the planner cannot control; "his proposal was nothing but a house of cards"; "a real estate bubble"