I pour up for Pimp C,
Most people pour liquor for their deceased homies when they die over their graves to pay their respects. Pimp C died of over-dose of cough syrup so instead of pouring liquor, he pours syrup, it could also mean Lil Wayne pours liquor in his cup and makes a toast to Pimp C.
Young Money (in particular Wayne and Drake) often reference UGK, to the point where Bun B (the other half of UGK), featured Drake on his track Put It Down — which had Pimp C being invoked LOTS of times.
Pimp C also did a song called Pourin Up.
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