An expression used to describe something that is über cool, awesome, amazing. From the slang word "rad" an abbreviation of 'radical'--made popular by the Teenage Mutant Ninja Turtles and skaters in the 80's. Being rad is the highest compliment you can give. Also used as an expression of awe.
by dds007 September 21, 2012
by John Scroyne February 14, 2007