What does idle roughness mean? what does it mean when a car is categorized as rough?

It means that the stroker engine has a radical cam. The more radical the camshaft, the more erratic your engine idle will be. The net effect can be that it idles so roughly that it sounds like it might stall at any moment as if the engine was barely running. A lot of car people think it sounds beautiful like that. Gives it an extremely mean sound. A radical sound. Personally I like it like that.