The term "Interagent" refers to an individual or entity that acts as a mediator between two or more parties or acts on behalf of another organization. Antonyms for this word could include words such as "opponent," "adversary," or "enemy," as these words suggest a level of conflict rather than cooperation. Alternatively, words such as "solo," "lone," or "individual" could also serve as antonyms for "Interagent," as they suggest a lack of involvement and coordination with others. Other related antonyms for this term may include "independent," "disconnected," or "isolate." Overall, the antonyms for "Interagent" suggest a lack of collaboration or relationship-building with others.