Big Fucking Gun. A POWERFUL munitions device seen mainly in Hollywood action and science-fiction movies, first sighted in possession of Colonial Marines in James Cameron's epic "Aliens" (1986); now seen in almost every dark-themed science-fiction or action film since. Dark, hulking, made of questionable metal alloys that do not exist yet. Fires: plasma, explosives, Big Fucking Bullets, anything it fucking well feels like.
Also seen in various anime films.
A popular user option in "Doom", and used vigorously in the feature film version of the game. Other names: Standard-Issue Big Gun, S.I.B.G., Big-Ass Gun, B.A.G., copwaster. For more details, visit Wikipedia entry "Aliens" (motion picture), and see paragraphs devoted to weapons created for and seen in the film.
Strongly desired by Daily Show host Jon Stewart, who during a "Doom"-related TDS interview with The Rock, claimed that he "got a hard-on" after temporarily gripping a B.F.G.; The Rock verified that Stewart indeed did get an erection after holding the weapon. Such is the power of the B.F.G.. If a B.F.G. can give Jon Stewart a hard-on, you would be wise not fuck with it.
"You get in my face, I will so waste your hillbilly ass with this B.F.G.."
Seen used in "Aliens" by Private Vasquez immediately following the line, "LET'S ROCCCCCCK!"