The term 'worker at the United Nations' can be summarized as a DIPLOMAT, which is an 8-letter word. A DIPLOMAT is a person who is appointed by a government to conduct negotiations and maintain relationships with other countries. Diplomats are typically sent to foreign countries to represent their home country's interests and to promote friendly relations. They are also responsible for negotiating treaties and agreements between countries. Diplomats must have excellent communication and negotiation skills, as well as a thorough understanding of international law and politics.