The Collaborative International Dictionary of English v.0.48:

Expatriate \Ex*pa"tri*ate\, v. t. [imp. & p. p. Expatriated;
   p. pr. & vb. n. Expatriating.] [LL. expatriatus, p. p. of
   expatriare; L. ex out + patria fatherland, native land, fr.
   pater father. See Patriot.]
   1. To banish; to drive or force (a person) from his own
      country; to make an exile of.
      [1913 Webster]

            The expatriated landed interest of France. --Burke.
      [1913 Webster]

   2. Reflexively, as To expatriate one's self: To withdraw from
      one's native country; to renounce the rights and
      liabilities of citizenship where one is born, and become a
      citizen of another country.
      [1913 Webster]

WordNet (r) 3.0 (2006):

expatriate
    n 1: a person who is voluntarily absent from home or country;
         "American expatriates" [syn: exile, expatriate,
         expat]
    v 1: expel from a country; "The poet was exiled because he
         signed a letter protesting the government's actions" [syn:
         expatriate, deport, exile] [ant: repatriate]
    2: move away from one's native country and adopt a new residence
       abroad

Moby Thesaurus II by Grady Ward, 1.0:

102 Moby Thesaurus words for "expatriate":
   DP, Ishmael, abstract, ban, banish, blackball, cast off, cast out,
   castaway, chuck, clear, clear away, clear out, clear the decks,
   cut, cut out, declasse, deport, derelict, disfellowship, displace,
   displaced person, dispose of, eject, elide, eliminate, emigrant,
   emigrate, emigre, eradicate, evacue, evacuee, evictee, exclude,
   excommunicate, exile, expel, expellee, extradite, flit, fugitate,
   get quit of, get rid of, get shut of, go from home, immigrant,
   immigrate, in-migrant, in-migrate, intermigrate, lag, leave home,
   leave the country, leper, liquidate, migrant, migrate, migrator,
   migratory worker, ostracize, oust, out-migrant, out-migrate,
   outcast, outcast of society, outcaste, outlaw, pariah,
   persona non grata, pick out, proscribe, purge, relegate, remigrate,
   remove, root out, root up, run, rusticate, send away, send down,
   send to Coventry, snub, social outcast, spurn, stateless person,
   strike off, strike out, swarm, take wing, throw over,
   throw overboard, thrust out, transmigrate, transport, trek,
   trekker, unacceptable person, undesirable, untouchable, weed out,
   wetback