Source : Webster's Revised Unabridged Dictionary (1913)

Migrate \Mi"grate\, v. i. [imp. & p. p. {Migrated}; p. pr. & vb.
   n. {Migrating}.] [L. migratus, p. p. of migrare to migrate,
   transfer.]
   1. To remove from one country or region to another, with a
      view to residence; to change one's place of residence; to
      remove; as, the Moors who migrated from Africa into Spain;
      to migrate to the West.

   2. To pass periodically from one region or climate to another
      for feeding or breeding; -- said of certain birds, fishes,
      and quadrupeds.

Source : WordNet®

migrate
     v 1: move from one country or region to another and settle there;
          "Many Germans migrated to South America in the mid-19th
          century"; "This tribe transmigrated many times over the
          centuries" [syn: {transmigrate}]
     2: move periodically or seasonally; "birds migrate in the
        Winter"; "The worker migrate to where the crops need
        harvesting"