The blob or smear of marijuana resin on your lips and/or tongue after smoking a hit from an uncleaned pipe or a fat gooey joint.
"Hey guy, you need to clean that pipe cause it's giving everyone resin rash."
"Shit man, that's good weed... two puffs on the doobie and I'm getting resin rash already."
"Shit man, that's good weed... two puffs on the doobie and I'm getting resin rash already."
by greenman61 December 6, 2013