Rad
Also known as: radical
Something really cool, sick or impressive. A classic of 80s skate slang.
Extended definition
"Rad" (short for "radical") is 80s skate/surf slang that's still alive: used for anything cool, gnarly or stylish — a trick, a board, a spot. It has a retro, affectionate edge, very old school. It's one of those words that gives away someone who's been at this a while.
Origin / etymology
Clipped form of "radical", popularized in 80s skating.