an island in the Gulf of Guinea that is part of Sao Tome and Principe
"The capital city sits on a small volcanic peak on the island of Príncipe, which forms part of São Tomé and Príncipe."
A surname.
"The Prince family, whose name is principe, has lived in that village for generations."
The word principe comes from Italian, where it originally meant a ruler or leader. It entered English usage as a doublet alongside the more common words "prince" and "princeps."