it's when you take a slice of american cheese (the kind that's in the wrapper) and stick it to the back of someone's shirt, usually near their shoulder, without the person noticing. you don't tell them the cheese is there until they're in a crowd of people and then you yell "CHEESE SHOULDER!"
Bob punched me in the face after I gave him a cheese shoulder in front of his girlfriend.
by that girl April 15, 2004
Get the cheese shoulder mug.