this is a jamaican word was not originated in london but is use frequently by londoners. this word is is the america equivalent to "oh shit". it is an exclamation that is usedwhen something suprising happens.
for example: rahted! where did that car come from or
rahted that guy jus got knocked the fuck out
or rahted that guy jus got shot for saying rahted originated in london when it camefrom jamaica to rahted!