The area that forms between a girls legs and her ass when standing in an upright position.
"Check out the gappage on that chick" or "Oi fellas, you could park a mini in her gappage, have a look!"
by Scottyp September 17, 2003
2 more definitions
Noun: angle of lifting of butt cheek to allow silent and comfortable escaping of gas from the bottom
Insufficient gappage will produce a deafening bottom bark.
by CathyV April 09, 2011
Moving quickly finding a new route maneuvering though gaps before they close
Driving down the motor-way weaving in and out of gaps forming the most efficient quickest route
by rc193 January 29, 2009