Source : Webster's Revised Unabridged Dictionary (1913)

Immigrate \Im"mi*grate\, v. t. [imp. & p. p. {Immigrated}; p.
   pr. & vb. n. {Immigrating}.] [L. immigrare, immigratum, to
   immigrate; pref. im- in + migrare to migrate. See {Migrate}.]
   To come into a country of which one is not a native, for the
   purpose of permanent residence. See {Emigrate}.

Source : WordNet®

immigrate
     v 1: migrate to a new environment; "only few plants can immigrate
          to the island"
     2: introduce or send as immigrants; "Britain immigrated many
        colonists to America"
     3: come into a new country and change residency; "Many people
        immigrated at the beginning of the 20th century" [ant: {emigrate}]