the process or act of migrating. a migratory movement:
preparations for the migration. a number or body of persons or
animals migrating together. Chemistry. a movement or change of
position of atoms within a molecule. Physics. diffusion ( def 3a
).  1605–15; < Latin migrātīon- (stem of migrātiō). See migrate,
-ion  migrational, adjective nonmigration, noun premigration,
adjective remigration, noun Dictionary.com Unabridged Cite This
Source Link To migration World English Dictionary migration
(maɪˈɡreɪʃən) 1.  the act or an instance of migrating  Collins
English Dictionary - Complete & Unabridged 10th Edition Cite
This Source Word Origin & History  1610s, of persons, 1640s of
animals, from L. migrationem (nom. migratio), from pp. stem of
migrare "to move from one place to another," probably originally
*migwros, from PIE *meigw- (cf. Gk. ameibein "to change"), from
base *mei- "to change, go, move" (see mutable). That Online
Etymology Dictionary, © 2010 Douglas Harper Cite This Source
American Heritage Medical D