Hey yo, you see that boy rockin those ugly yellow shoes? They look like sauce.
Hey man, you hear how my girl broke up with me for another guy? That's some sauce.
Adjective describing something wak. It's root is unknown, but it's meaning resonates to belittle something or someone. To emphasize how sauce someone or something is, it can be modified by "straigh" as in straight sauce.
Nick: "What are you doing tonight, Mike?
Mike: 'I'm chillin with my boy, Meatball. You wanna roll through?