Immigrate, v. t. [imp. & p. p. Immigrated; p. pr. & vb. n. Immigrating.]
Etymology: [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.
Shades of meaning
Fernald has no entry of its own for immigrate; he lists it under emigrate.
Where he writes about it:
Emigrate and immigrate carry the idea of a permanent change of residence to some other country or some distant region; the two words are used distinctively of human beings, and apply to the same person and the same act, according to the side from which the action is viewed. — from emigrate