To suddenly release a fart in such a way that an unsuspecting victim is lightly 'dusted' with the gas molecules. This can be done in two ways, by either walking in front of the recipient as you let 'er rip, or by planting the bomb booby trap style in such a manner that they unknowingly walk through it.
Man, I totally just cropdusted you. At least it's better than a Covered Wagon.
In a wilderness/natural environment, a covert phrase to indicate the need to relieve your bowels.
Hiker One: Hey, look at that beautiful view!
Hiker Two: Yes, great, it's just great; you should keep looking at it while I go check my traps...
Hiker One: Ok! (knowlingly sits against a tree and starts doing MadLibs)