Don't use this adjective in any circumstance. Of course using it as a noun is perfectly acceptable. For instance, you are referring to the outstanding 1986 film of the same name, starring, among others, the beautiful Lori Loughlin and Bart Conner. Yep, that gymnast plays the antagonist. In all circumstances when "rad" is used as an adjective you are trying too hard to sound hip, which means you sound like a tool.
