Antonyms for the word "co-operated" can be described as actions or behaviors that oppose or work against co-operation. These antonyms include words like clash, conflict, compete, obstruct, oppose, resist, and sabotage. When an individual or group refuses to co-operate, it can lead to disharmony, tension, and conflicts. This can occur in personal or professional settings, such as between employees or in relationships. In contrast, co-operation is necessary for positive outcomes and productive results. Therefore, fostering co-operation through communication, negotiation, and compromise can lead to successful outcomes and stronger relationships.