For a royal princess:
* Aliʻi wahine: This literally means "noble woman" and is used for a female member of the chiefly class.
For a princess in a more general sense:
* Keiki aliʻi wahine: This means "child of a noble woman" and could be used for a young princess or a princess who isn't necessarily of royal blood.
* Moʻi wahine: This means "queen" and could be used figuratively to refer to a princess, particularly if she has a strong and powerful personality.
Ultimately, the best way to say "princess" in Hawaiian would depend on the specific context and the nuance you want to convey.