naturalize

Short definition from Wiktionary

Verb

1. 1
   To grant citizenship to someone not born a citizen.
2. 2
   To acclimatize an animal or plant.
3. 3
   To make natural.
4. 4
   To limit explanations of a phenomenon to naturalistic ones and exclude supernatural ones.
5. 5
   To make (a word) a natural part of the language, using the native homologue of each phoneme (and often for each morpheme) of the imported word (e.g., native inflections).
6. 6
   To study nature.