Kinktionary
More like guidelines and a lot less like definitions.
Princess
In BDSM, a princess is a role, most commonly a submissive role. It is considered by some people to be a sub-type of brat and is sometimes described as "A babygirl with a backbone." However, behavior types and styles can vary extensively within this role and some people in this role may enjoy more of a switch dynamic or use this role to identify as a type of Dominant 'Little.
A princess often has a desire to be spoiled to some degree, although this is not by definition always materialistic. Gifts can be verbal, praise, compliments, physical touch, etc.
A princess can have high standards both for themselves and their partners and will often worship their partner and do whatever they can to please them.