Urban street talk that many young dudes use around London. It's used to describe something that is both crazy and also extreme, in a hip, to-the-max kind of way.
Tommy - "Yo dude! I'm like going to totally 360 over this Austin Allegro on a baking tray!"
Billy - "Woah boi! That's totally Radiculas."
Billy - "Woah boi! That's totally Radiculas."
by Concise Oxford Dictionary August 24, 2007