naturalize.

To grant citizenship to someone not born a citizen.

To acclimatize an animal or plant.

To make natural.

Custom naturalizes labour or study.

To limit explanations of a phenomenon to naturalistic ones and exclude supernatural ones.

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).

In English, foreign words are typically written in italics until they are naturalized.

English speakers have naturalized the French word "café".

To study nature.