To drop dirty bombs on a imaginary ship in the toilet bowl.
To defecate.
"This Crohn's is murder, I've had to bomb the Bismark 3 times this morning."
or
Tim: "Where are you going Tom?"
Tom: "Bombing the Bismark, that bran has gone right through me!"
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.