Pronunciation: (mī-grā'shun), [key]
1. the process or act of migrating.
2. a migratory movement: preparations for the migration.
3. a number or body of persons or animals migrating together.
4. Chem.a movement or change of position of atoms within a molecule.
5. Physics.diffusion (def. 3a).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.