1. The act of seceding.
2. often Secession The withdrawal of 11 Southern states from the Union in 1860-1861, precipitating the U.S. Civil War.

[Latin sēcessiō, sēcessiōn-, from sēcessus, past participle of sēcēdere, to secede. See secede.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.