I looked up piha and yes, it means "to eat oneʻs fill." It also means "pregnant," so I can see a woman might want to be careful about announcing sheʻs piha after dinner. Other than that, if *māʻona means full (of food), satiated, satisfied, is it ever used in place of "kena" which also means satiated and satisfied as well as to quench oneʻs thirst? Or do those two words clearly differentiate thirst vs. hunger?
Thanks. Most of the time, "piha" means full. "Ko'u inoa piha" means my full name, and "piha makahiki" is a full year. Pregnant is most often "hapai." If a woman announced she is "hapai" after dinner, I think there would be a pretty big reaction from the table. As far as "kena," I would gamble that it is much like English. If you are no longer hungry, it is likely you are no longer thirsty. If you are no longer thirsty, there is a good chance you might still be hungry.