Pakistan
noun: Pakistani(s)
adjective: Pakistani

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