A large, long-barreled, high-power handgun, preferably a revolver. From the comic book Preacher where the villain, Starr gets his junk bitten off by a trained Rottweiler and compensates with an obsession with large handguns. He stands in front of the mirror, holding his gun at groin level, saying "doom cock".
Doom cock.
DOOM COCK!
DOOOOOOM COOOOOOCK!!!!!!!!!

That .500 S&W is a fucking doom cock.
Here's where Dirty Harry pulls his doom cock.
by Dr. Badwrench April 5, 2008
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Insertion of penis into each ear hole. One penis per ear hole equaling a total of two penises inserted into the head at once.
At Western Illinois University, a young woman was doom cocked in the elevator by Mark and Max.
by MaxBotkin April 2, 2008
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