secede

/sɪˈsiːd/
verb
  1. To formally leave a political union, organization, or alliance.
    • The region voted to secede and form its own independent country.
    • Some members threatened to secede from the club if the rules were not changed.
    • Several southern states decided to secede from the Union in 1861.
Antonyms
What does "secede" mean? | whatsthatwordmean | whatsthatwordmean