Definition of: migration

(mī·grā′shən) noun
1. The act of migrating.
2. The totality of persons or animals migrating, or the time occupied in migrating.
3. Chem. The removal or shifting of one or more atoms from one position in the molecule to another.
4. Physics The drift or movement of ions, under the influence of electromotive force, toward one or the other electrode. [<L migratio, -onis]
—mi·gra′tion·al adjective
—mi·gra′tion·ist noun