1. verb- to jab one's fingers into the stomach of another, and as they are bent over in pain, to hit them down with a blow to the back of the neck with one's elbow. Usually accompanied by the yell of "SHAMPAM!"
2. noun- the pain you are left with after someone has shampammed you, or a metaphorical feeling, as though someone has just shampammed you.
1. "Hey dude, whatsu--"
"Ow! Christ, man! What'd you shampam me for?"