noun
annexation
an-ek-SAY-shuhn/ˌænekˈseɪʃn/
The act of adding territory or property to a larger entity.
The proposed annexation would bring the village within the city's boundaries.

Etymology
The roots picture binding one thing to another, and the ending names the action. This developed into adding a smaller territory to a greater one through formal control.
In context
But I surely don’t support the annexation of Crimea because it was a way for Putin to express his power and raise the level of patriotism in souls of Russian vatniks. But as Russian authorities consider Crimea Russian territory
More examples
- Residents debate the consequences of annexation.
- The historian maps several territorial annexations.
- The agreement sets conditions for the annexation of the property.
Forms
annexation · annexations
Similar words
- incorporation
- Broader joining into a whole, without necessarily changing territorial control.
- acquisition
- Emphasizes obtaining something rather than adding it to an existing entity.