naturalization

Cultural  

1. The process by which a foreign citizen becomes a citizen of a new country. Millions of immigrants to the United States have become American citizens. Requirements for naturalization in the United States include residency for several years, ability to communicate in English, demonstrated knowledge of American history and government, and a dedication to American values that includes no membership in subversive organizations, such as the Communist party.

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Explanation

Use the noun naturalization to describe what happens when someone becomes a brand new citizen of a country. If you're born in one country but want to become a citizen of another, you'll have to go through the process of naturalization. There are certain rules and processes involved in naturalization, depending on the country, but you usually have to live there for a certain number of years and swear an oath of loyalty. When biologists use the word naturalization, they're talking about moving plants or animals to a new place where they can thrive.