1. to add or attach something to a larger or more important thing
2. to take control of a territory and add it to one’s own country or state

1. a building that is added to or connected to a main building

Examples

• The library will annex the old gymnasium to create more study space.
• Russia annexed Crimea in 2014.
• The treaty allowed the empire to annex several neighboring territories.
• Please annex your resume to the application form.
• The school built a new annex to house additional classrooms.
• The hotel annex provides extra rooms for guests during peak season.
• They converted the garage annex into a home office.