This is the slang word for Jolly Rancher Candies. Much like the many alternate words for drugs, Slanderous J can be used amongst authority figures to stay "below the radar."
Dude 1: Hey man you wanna hook me up with some Slanderous J?
Dude 2: For sure bro
Dude 1: Thanks alot dude
Dude 1: No problem
Slanderous J. a drug? Nope, but its got a pretty good name for one
really its just jolly ranchers and people use the name to scare there friends into thinking the are stoners...
"hey lets go get hooked up with some slanderous J."
"What? is that the new name for crack?"
"nope, just jolly ranchers"!