"League of Nations union" can be described as an international organization that aims to promote peace and cooperation among its member countries. Some synonyms for this term include International Federation for Peace and Sustainable Development, Global Alliance for Peace and Sustainability, United Nations Association, and World Federation of United Nations Associations. These organizations share a common goal of fostering peaceful relations among nations, promoting sustainable development, and advocating for human rights. They work to maintain communication and collaboration among member countries through various programs, conferences, and partnerships, and strive to create a more just and equitable world for all.