it is a (slang) flatulence.and (noun) flatulence means
The state of having gas, often malodorous, trapped (and often released, frequently with noise) in the digestive system of a human and some other animals; wind; and when released, a flatus, a fart.
The release of such gas, farting.
so in others its basically gas within the digestive system that can come up as a fart or burp hope this helped :D...
