The word "round" is used colloquially in many ways, mostly in the sense of beeing “round like a circle” (→circular or ring-shaped), “round like a roll or drum” (→cylindrical) or “round like a ball” (→spherical) and often only as a distinction from the “regular” shape of the objects, e.g. beeing “round, not rectangular” or beeing “round, not flat” or being “round and not having edges”. So possible meanings of “round” are: