naturalize

transitive verb naturalized, naturalizing

1. to confer the rights of citizenship upon (an alien)
2. to adopt and make common (a custom, word, etc.) from another country or place
3. to adapt (a plant or animal) to a new environment; acclimate
4. to explain (occurrences) by natural law, rejecting supernatural influence
5. to make natural or less artificial; free from conventionality

intransitive verb

1. to become naturalized, or as if native
2. to study nature