Being undisputed is defined by the absence of disagreement. In common usage, it describes a fact or person generally accepted as true or superior. The "Four-Belt" Era: In professional boxing, the undisputed champion must hold all four major world titles: the Unified vs. Undisputed: champion holds two or more belts, but an undisputed champion has "collected" them all. A History of the Heavyweight Crown

Mixed martial arts uses a different model: one champion per weight class, making every champion "undisputed" in a narrow sense. Yet fans still debate whether a champion has beaten all credible challengers. Thus, undisputed is a function of organizational recognition, not universal acclaim.