To give permission, power, or the legal right to do something.
To give someone more confidence and/or strength to do something, often by enabling them to increase their control over their own life or situation.
To grant citizenship to someone not born a citizen.
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).
To study nature.
To limit explanations of a phenomenon to naturalistic ones and exclude supernatural ones.
To acclimatize an animal or plant.
To make natural