5: Def - There was one brief, glorious moment where everything was def. Poetry jams, comedy, even rappers (of whom, the most def was Mos Def, obviously). Then in an instant, it was gone, supplanted by fresh, and phat, and others. But we remember you, def, and we miss you... (Couldn't find a vid of this one--can you believe it? Will Smith said "def" about 8 million times during the run of The Fresh Prince of Bel Aire, but I can't find a single one.)
Noticeably absent from the list is "tubular." Don't. Just don't. If you have any rad comments about words that mean "cool," share them below. And share this with your friends on Facebook--they'll think you're dope!