When there's so much garbage in the trash can, and you don't want to take it out, so instead you compact it as much as you can by crushing it back down deep into the can.
"Hey man, you need to take the trash out."
"Nah man, I'lljustuse garpaction."
When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).