The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]