1. The act of disjoining or the condition of being disjointed.
2. Logic.
   1. A proposition that presents two or more alternative terms, with the assertion that only one is true.
   2. A proposition that presents two or more alternative terms, with the assertion that at least one is true.
3. Genetics. The separation of homologous chromosomes during meiosis.

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.