jimmy: did you get that chron yet?  zack: ya, but it turned out to be some of them dirty 30s
[marijuana] that is over priced, often sold as [chronic] (30 a half eighth 60 an eighth) when it is actually mid grade [weed] (20 a half eighth 60 an eighth)
"jimmy: did you get that chron yet?  zack: ya, but it turned out to be some of them dirty 30s" What is the definition of "dirty 30s"?