secession (n.)

1530s, from Latin secessionem (nominative secessio) "a withdrawal, separation; political withdrawal, insurrection, schism," noun of action from past participle stem of secedere "go away, withdraw, separate; rebel, revolt," from se- "apart" (see secret (n.)) + cedere "to go" (from PIE root *ked- "to go, yield"). Originally in a Roman historical context, "temporary migration of plebeians from the city to compel patricians to address their grievances;" modern use in reference to religious or political unions dates from 1650s.

Origin and meaning of secession

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Definitions of secession from WordNet
secession (n.)
an Austrian school of art and architecture parallel to the French art nouveau in the 1890s;
Synonyms: sezession
secession (n.)
formal separation from an alliance or federation;
Synonyms: withdrawal
Secession (n.)
the withdrawal of eleven southern states from the Union in 1860 which precipitated the American Civil War;