noun (n)

• migration from a place (especially migration from your native country in order to settle in another)(noun.act)

  Synonym:
  expatriation, out-migration
  

  source: wordnet30
• The act of emigrating; removal from one country or state to another, for the purpose of residence, as from Europe to America, or, in America, from the Atlantic States to the Western.(noun)

  source: webster1913