Depending on who you ask this has 2 possible definitions:
a) Torture, horrible torture equivalent to spikes shoved up the finger nails, slowly pealing skin off of a person, or hobbling someone like that scary chick from misery.
b) A silly prank the military plays on their terrorist buddies at the big fun BBQ palace known as Guantanamo Bay
Bush is a total doucher for using waterboarding on those poor Muslims in his silly crusade again all religions other then his own.
Man, the military and those terrorists look like they are having so much fun over at their party. They get to bob for apples, play pin the tale on the donkey, have a tickle contest, and enjoy some fun waterboarding.