Pronunciation: (dē"ku-sā'shun, dek"u-), [key]
1. a process of becoming or condition of being crossed in the form of an X.
2. Anat.a nerve or tract of nerve fibers that crosses from one side of the central nervous system to the other.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.