rancid

When a particularly sick burn is wrought, a hype-man (or woman) may exclaim "That's straight up rancid" to indicate their assent as to the magnitude of the damage. Etymology derives from the process of meat putrefaction. Word typically employed by dashing young rogues

Bob (to impending burn victim): Dude you look like the kid from Home Alone grew up and became a hobbit
Neutral third party (awed): Damn man - that's straight up RANCID