naturalization

from The Century Dictionary.

• noun The act of naturalizing, or the state of being naturalized; specifically, in law, the act of receiving an alien into the condition, and investing him with the rights and privileges, of a natural subject or citizen.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act or process of naturalizing, esp. of investing an alien with the rights and privileges of a native or citizen; also, the state of being naturalized.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The action of naturalizing somebody.
• noun The admission or adoption of foreign words or customs into general use.
• noun The introduction and establishment of an animal or plant into a place where it is not indigenous.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the proceeding whereby a foreigner is granted citizenship
• noun the quality of being brought into conformity with nature
• noun the introduction of animals or plants to places where they flourish but are not indigenous
• noun changing the pronunciation of a borrowed word to agree with the borrowers' phonology