Plural of "prince":
* PRIN-ses - This is the most common pronunciation and is used when referring to multiple male rulers or noblemen.
Verb "to prince":
* PRINTS - This pronunciation is used when referring to the act of reigning or ruling like a prince. This usage is less common and often considered archaic.
So, if you're talking about multiple princes, you'd pronounce it PRIN-ses. If you're using it as a verb, you'd pronounce it PRINTS.