naturalize

Universal Words (BrE also naturalise) verb [usuallypassive] 1 [VN] to make sb who was not born in a particular country a citizen of that country: a naturalized American who was born in Poland * He was naturalized as a British citizen in 1940. 2 [VN] to introduce a plant or an animal to a country where it is not native: The grey squirrel is now naturalized in Britain. 3 [V] (of a plant or an animal) to start growing or living naturally in a country where is it not native naturalization, naturalisation noun [U]: naturalization papers (= documents that prove a person has been made a citizen of a country)