1. the administrative office or department of a large organization, especially an international body
2. the staff working in such an administrative office

Examples

• The UN secretariat is headquartered in New York.
• She works for the secretariat of the World Health Organization.
• The secretariat prepared all the documents for the summit.
• Members of the secretariat coordinated the international conference.
• The organization’s secretariat handles day-to-day operations.
• He was appointed to head the new secretariat.
• The secretariat issued a statement on behalf of the committee.