When reading from a back issue of American Whitewater I came across the word "gnarly" printed boldly in black and white. On the cover.
Fortunately I went down the Colorado River through the Grand Canyon earlier this year with three whitewater kayakers who spat out words and phrases like "shredding the gnar," "are you ready for the gnarlsberg cheese," "gnarlsberg and crackers," and listened to them use "bro" as an adjective. For example, "that surf hole/wave/ledge hole/pour over is totally bro."
Therefore the adaptation of strange slang vocabulary used by brotastic athletes in extreme sports is completely familiar to me, especially since I started climbing two years ago and began hearing or using odd terminology. "Burl nugget" being the strangest, don't even ask me what it means, and "psyched" being the word I probably use the most.
On another note I seriously want to get back into whitewater kayaking. Hella.