绥宁县 is formed by combining three characters: 绥 (suí), which means "pacify" or "calm", 宁 (níng), meaning "peace" or "tranquility", and 县 (xiàn), meaning "county". The name derives from historical context where "绥宁" was chosen to convey the concept of pacification and enduring peace in the region, with "县" designating it as an administrative county.