Naturalization (noun)

1. The process by which a person not born in a particular country is granted citizenship.
2. The process of making something more natural or familiar.

Origin:

From latin naturalizatio, from naturalis "relating to nature", from natura "nature".

Examples:

1. He applied for naturalization to become a citizen of the country.
2. The naturalization process can take several years.
3. Many people have gone through the naturalization process in order to vote in elections.
4. The naturalization of the immigrants was celebrated in a ceremony.
5. The naturalization of the new plant species was welcomed by botanists.