The superior form of "retarded". It's the most destructive word you can ever use against another living soul. Saying this word to someone will cause them to either die of a heart attack or become so sad that they commit suicide.
Random Person on the Internet: "Oh boy a new comment on my Youtube video!"
Edgelord9000: "You are rarted!"
Random Person on the Internet: *dies of heart attack*
The absolute worst insult you could ever, ever say. Nothing could ever top this insult, and if it doesn't completely obliterate the victim, it will leave them soulless, damned to walk this Earth forever.
Greg: Hey dude what's up
Josh: Dude shut up you are rarted
Greg: *Fades into non-existance*