Originates from Cuban Spanish. Refers to a "lowlife", a cheazy (cheap & sleazy) person, someone with little or no class who often dresses the part, as well - using big, gaudy, overly showy clothing & accessories.
"Mira a ese reloj chillon que lleva Cuco. Y mira como habla con boca grande y con tanta vulgaridad. Que gente mas chusma!"
"Look at that big, gaudy watch Coco wears. And look at how he goes around talking all big and with such vulgarity. What a lowlife!"