air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
breathing device consisting of a bent tube fitting into a swimmer's mouth and extending above the surface; allows swimmer to breathe while face down in the water
(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";