The Big Fucking Gun (or more politely, Big Freaking/Fragging Gun) found officially in all of the high-profile id Software games like Doom and Quake. Fires a very large green ball of man-made lightning and then upon impact, the weapon instantly releases a huge spread of energy to anyone that the BFG'er is facing. (Despite how extensive this definition is, it is loose.) In Quake II, the ball of energy will shoot lasers a certain distance for some additional pain.
Newbies hate the weapon, but some veterans consider the BFG a thinking man's weapon (in deathmatch)because of its strange behavior, slow firing rate, and high energy drain.
Grasshopper couldn't hide from ShadowFox's BFG.
Neo was disintegrated by Bar3Star's BFG.
by prdarkfox May 5, 2005
the BFG9000 was the most powerful weapon in the doom video games. it originally stood for "Big Fucking Gun" as explained in the game's design document. the quake games pay tribute to the gun with the BFG10k. in the recent doom motion picture, the gun is denominised on a computer screen as "Bio Force Gun".
"the BFG is the key weapon in doom's final level"
by noodlemantra March 28, 2006
Kids: Big Friendly Giant

Teens and up: Big Fucking Gun, from Doom series
eat this fucker!!
by Whale Watcher June 6, 2003
big fucking gun such as in DooM and Quake, and some various mods for other games.

Sucks in Quake 3
Arwing should have used a smaller gun
by arwing September 28, 2003
Kids: Big Friendly Giant
Teens and Over: Big Fucking Gun
Tall Gingers: Big Friendly Ginger
Kids: Mummy the BFG is on the telly
Teen: Fucking Hell, look at that BFG
Tall Gingers: I'm the BFG!
by DM214 April 6, 2007
Big Fucking German. Used to describe a German of large stature, whose size comes in handy when decimating his opponents. You can recognize a BFG when they get drunk and want to wrestle. However, BFG's are not always violent, since they also wear pink polos, listen to classical music, and enjoy long walks at sunset.
Holy shit man, did you see Peter fighting in the club last night? I thought he was so chill since he asked Bertha on that sunset date. He must be a BFG!
by chiz69 December 12, 2011
basil funny games, used to refer to mutual masterbation with a bff you spend every waking and wanking moment with. Can often result in being late to work and/or lab
"Yo dude, sorry I'm late man"
"A little BFG time back at the dorms?"
"Naw way bra, I had to put on my lotions"
by The Duck August 26, 2007