Other forms: princeliest; princelier
Something princely is controlled by or suits a prince, like a princely territory or a princely velvet cape.
If a prince (a male royal, often the son of a king or queen) rules certain areas, they are princely territories. And if a prince wears certain clothes, you could say he sports a princely outfit. You can also use this adjective to mean "fancy" or "opulent," so you might describe the princely furnishings in your elegant hotel room or the princely offerings on the menu at a four-star restaurant.