A term widely used to describe some stupid
and/or downright insane
stunt that is nevertheless hilarious
and witnessed by at least one other person, preferably a group of people and recorded on video.
The term originates from the MTV pop culture reality series "Jackass" which features a group of several early to mid-twenty year old men who perform a number of such stunts as mentioned beforehand, mostly in public and involving a number of people in the group.
Due to the high popularity of the show and widespread fanbase, the term "jackass" has morphed from, what the Webster dictionary's 1913 edition defines as a "conceited dolt" or "perverse blockhead" to "cool dude". In an effort to emulate the cast of the TV series, boys from ages 8 to 28 often try to gain respect from their peers by performing any number of highly reckless stunts to create that perfect "jackass moment" where the person performing said stunt is compared to one of the characters from "Jackass". Often enough, though, these moments can easily happen by accident, such as the classic Slipping on a Banana Peel or more modern Smashing of Genitalia After a Failed Railslide. This will typically be accompanied by an awed outburst from witnesses, along the lines of: "Woah, that was a total Jackass moment, dude!"
A large portion of such fame-seekers will actually set a stage for their Moment. They develop a plan as how to maximize humor potential whi le trying to keep a large risk factor involved, such as criminal persecution, personal injury, death or most importantly humiliation. Optionally, a video camera will be used to record the Moment so as to prove the existence of it at a later time. Due to the professionalism of the series, and relative inexperience of these amateur imitators, the consequence of many of these stunts results in jail sentences, extreme pain and/or death. Which, of course, may positively effect the amount of respect the stuntee receives from others.