what does it mean to annex

To annex means to add or attach something, especially a territory, to a larger entity such as a country or state. It often involves taking control of a territory or area and incorporating it into one's own domain, sometimes by force or political action. Annexation usually refers to the act of a country adding land to its territory. The term can also be used more generally to mean attaching or appending something to a larger thing, such as an annex to a building or a document appendix.