To expel
gas from the
stomach through the
mouth. Sometimes you burp because some of the
air you breathe makes it down the wrong pipe. Sometimes you burp because you've been
drinking
carbonated soda. It's a
necessary and
common body function -- the stomach was just not designed to hold and store gasses -- but it's considered very
impolite in Western society.
Some folks make
dainty burps, some burp like
cannons. Some people can burp on
purpose and on
command, by swallowing air and then letting it
loose, but others just don't have the
knack.
Burps are funny.