- In modern diplomacy, opportunity for political and commercial intercourse open to all upon equal terms, especially with reference to a nation whose policy is wholly or partially fixed by nations foreign to itself or to territory newly acquired by a conquering nation. In this sense, often used adjectively, as, open-door system, open-door policy, etc.
- Open or free admission to all; hospitable welcome; free opportunity.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). open door. Retrieved September 22, 2026, from http://smartdefine.org/open_door/definitions/2038959 |
| Chicago | Webster's. 2011. "open door" http://smartdefine.org/open_door/definitions/2038959 (accessed September 22, 2026). |
| Harvard | Webster's 2011, open door, Smart Define, viewed 22 September, 2026, <http://smartdefine.org/open_door/definitions/2038959>. |
| MLA | Webster's. "open door" 27 May 2011. Web. 22 September 2026. <http://smartdefine.org/open_door/definitions/2038959> |