"Slim Dunkin" refers to a female with a large posterior that is disproportionate to her thin waist.
In remembrance of slain rapper Slim Dunkin, and out of appreciation of healthy girls with large posteriors.
Jerome: " Ayo Melo!"....."Loook at shorty over there she's trim and she has a big ass booty!"
Melo: *looks* "Yeah my nigga, she Slim Dunkin!"