A formal document or agreement through which a state, territory, or region agrees to join or become part of another political entity, typically a larger country.

अधिग्रहण का उपकरण

English Usage: The royal decree served as the instrument of accession for the region to join the new federation.

Hindi Usage: राजा का आदेश क्षेत्र के नए संघ में शामिल होने के लिए अधिग्रहण के उपकरण के रूप में कार्य करता था।