Greetings, I have a peculiar terminological issue. In a research paper I am writing, I need to distinguish between rolling wheels and rolling balls. The relevant difference for my purposes is that a wheel rotates around a single axis whereas a ball rotates around a single point. It's straightforward enough to refer to the locomotion of a wheel as " wheel locomotion" or more simply "wheeling," but "ball locomotion" seems awkward at best, and it goes, er, downhill from there! It occurs to me that there may already be terms out there that are used to refer to and distinguish between "the rolling motion of a wheel" and "the rolling motion of a ball." I'm a biologist, and not a physicist, though, and I don't seem to know how to track down these terms, if they exist. Any suggestions would be greatly appreciated!