Ratjacket is a reputation or 'jacket' for snitching. Once acquired, a ratjacket is typically permanent. In the office and other environments where people become well-known to each other, the ratjacket is a form of social leprosy and can lead to ostracization and worse.
Emma noticed a chilly social thermostat at the office. To her horror, Emma realized she had a ratjacket after singing to management about Jenny and Heather's time-card collusion.
A young, suburban, white man who chain smokes squares, drives a maroon Chevrolet Lumina, and dons a "New Years 2000" top hat (among other things) upon becoming intoxicated.
Cool kid: "Who's that guy listening to the J.G. Wentworth commercial very loudly in that late-90s model sedan?"