1. the person who holds the secretaryship of the Interior Department - President Taylor appointed Thomas Ewing as the first Secretary of the Interior • Syn: Secretary of the Interior • Hypernyms: secretary 2. the position of the head of the Department of the Interior - the position of Interior Secretary was created in 1849 • Syn: Secretary of the Interior • Hypernyms: secretaryship • Member Holonyms: United States Cabinet, US Cabinet