The condition in which, due to an extreme exposure to an event of epic Awesomeness, Horror or any other emotion on the more extreme end of the spectrum of emotions, one loses all perception of space and time including (but not limited to) a brief lapse in physical awareness. Such an emotional rush can even override Pain, which in some cases may be the cause of the rush.
In addition to being common among the disciples of Metal and among those who get so stoned that they can't feel certain parts of their bodies (such as their faces), it takes on somewhat of a more literal sense if one happens to plaster a White Phosphorus or Acid Grenade on the face of someone annoying them (some Nazis in a certain famous movie learned this the supernaturally hard way...in any case, you really shouldn't mess with White Phosphorus or dangerous Acids except for in Video Games).
While they writhe in pain, it may be customary to say the hilarious-but-somewhat-stupid phrase below:
Enemy n00b: "ARRGH my head asplode!"
You: "Would you like a Guitar Solo with that Face Melting!?" (proceeds to mime awesome solo on Air Guitar)
The event commonly found in action movies wherein all present in a particular scene pull out firearms (often high-caliber) and start spraying hot lead at each other for the next few minutes. Such scenes are known to result in high body counts and more counts of Attempted Murder per minute than a good Auctioneer can get out Words per minute.
Frequent features of these scenes include how the Protagonist of the film mysteriously never has to reload during the scene or else has the ability to fire his otherwise Semiautomatic pistols at the rate of Miniguns while suffering no penalty to Accuracy attributed to Recoil. In addition, if he DOES have to reload during the scene, extra clips and replacement weapons are always conveniently placed around the area of the firefight. Enemy forces have astounding accuracy, but only in regard to their mutual interest in kicking up dirt around the Protagonist's feet as they run for cover as opposed to being interested in actually hitting the Protagonist. Lastly, most enemy forces appear to be wearing body armor with the density and effective protection factor of Pillows and also seem to be little more than semi-intelligent 50-gallon bags of pressurized blood.
The Bulletfest has been a mainstay of action movies since the 1970s and has been responsible for such things as the "R" movie rating, among others. It is almost always the most unrealistic, but simultaneously the coolest, event of most action movies.
Yeah, that Bulletfest at the end of the movie was so unrealistic, there were guys dropping even when there were no bullets being fired. It was still pretty cool, though.