A person of good intention who attempts to change ignorant laws that are biased against cannabis and toward arrest and incarceration of people that cure, or lessen, the effect of pain associated with many diseases and ailments where pharmaceuticals do not work without grave side effects.
A person who is well-versed and educated in all things having to do with the culture of pot, marijuana, cannabis, weed, etc. This can include, but is not restricted to weed dealers, bong shop owners, musicians, Rastafarians, hippies, grow-house owners... It can also be used as a more respected label than the more commonly used terms, stoner or pothead.
Judd Apatow's films always have some kind of reference to marijuana. He's a true cannaphile.