When a person is so thick their legs (thighs to cankles) are thick as tree trunks. Can also be called trunks for short.
Person 1: wow, she thicka than a snickaz...
Person 2: yea, shes got a serious case of trunks.
Doctor: I'm sorry miss, you've been diagnosed with trunks disease.
Woman: Noooo!! is there a way to cure it?
Doctor: Yea, it called a stairmaster, bitch.