Secession /(sē̇*sĕsh"ŭn)/

Se·ces·sion

Secession

n.
  1. The act of seceding; separation from fellowship or association with others, as in a religious or political organization; withdrawal.
  2. The withdrawal of a State from the national Union. (U.S. Hist.)

Phrases & Compounds
Secession Church
(in Scotland). See Seceder.