Deconcentrate refers to the act of dispersing or decentralizing something. So, the antonyms for deconcentrate would be words that denote bringing things together or centralizing them. Some of the antonyms of deconcentrate could be "concentrate," "centralize," "unify," "consolidate," "gather," "assemble," "cluster," "focus," and "amass." These words imply a more centralized approach rather than a dispersal or decentralization process. For instance, in organizations, managers may choose to concentrate power and resources in a single location rather than deconcentrating them. Similarly, in urban planning, some planners might choose to centralize development rather than dispersing it throughout the city.