Lean, sizzurp, drank, purp, in other words, its dat weak opiate drink that gets you chopped an screwed. The other definitions on UrbanDictionary include the usage of jolly ranchers, popularized in some hip hop songs and even the inclusion of benzodiazepines (xanax, valium, etc) to push that sedated high one step further.
Im not telling you not to mix your drank with liquor or benzos, but the fact is: dirty sprite = drank. Drank is just purple codeine + promethazine cough syrup poured into some sprite or 7-up. It can also be used to describe yellow hydrocodone + chlorpheniramine mixed with the same kinds of soda. The point is -- its opiate cough syrup in a clear soda, drunk to slow you down and screw up your night.
Take it easy, opiates are serious business. I've been clean of that shit for years, but the definitions on UD are all kinda fucked, so, here's the real one for you.
My niggas gettin' right, smokin weed with dirty sprite. I'm goin' wild for the night fuck being polite.