When something is unbounded, it has no limits or boundaries. Therefore, antonyms for this word would be closely related to limits and boundaries. Some words that can be used as antonyms for unbounded are bounded, limited, confined, restricted, regulated, restrained, and defined. When something is bounded, it has specific borders and cannot exceed them. Similarly, when something is limited, it means that there are boundaries that prevent it from growing or increasing beyond a certain point. When something is confined, it has physical or mental barriers that restrict its movement or expression. The antonyms for unbounded help us understand the concept of confinement and restriction as opposed to freedom and expansion.