Palau
noun: Palauan(s)
adjective: Palauan
Panama
noun: Panamanian(s)
adjective: Panamanian
Papua New Guinea
noun: Papua New Guinean(s)
adjective: Papua New Guinean
Paraguay
noun: Paraguayan(s)
adjective: Paraguayan
Peru
noun: Peruvian(s)
adjective: Peruvian
Philippines
noun: Filipino(s)
adjective: Philippine
Pitcairn Islands
noun: Pitcairn Islander(s)
adjective: Pitcairn Islander
Poland
noun: Pole(s)
adjective: Polish
Portugal
noun: Portuguese (singular and plural)
adjective: Portuguese
Puerto Rico
noun: Puerto Rican(s) (US citizens)
adjective: Puerto Rican