Help with a question about Smoking.?

I would like to know what a "Jay" is, my friend told me he got kicked out of school for smoking a Jay so.. What is it..?? ...

jonniesparko	Bad stuff, stay away from J!!!!
J. Luke	A joint. He smoked marijuana.
kay_flood	"J" for "joint", he was smoking marijuana
mikki080	J is Pot or Marijuana. Its short for "Joint"
Hat Trick - Agnostic Missionary	aka budda, buds, pot, weed, mary jane, sensamilia, herb, marijuana.
....	"jay" is also known as a "mary Jane" it's marijuana