diocese, economy, parish, parochial
Oikos (house, household)
anonymous, antonym, synonym
Onoma (name)
orthodox, orthography
Orthos (straight, right, correct)
dioxide, oxidize, oxygen, peroxide
Oxys (sharp, keen)
encyclopedia, pedagogue, pedant
Pais, paid- (child)
panacea, pancreas, panegyric, panoply, panorama, pantheon, pantomime
Pas, pant- (every, entire, all)
antipathy, apathy, pathetic, pathos, sympathy
Pathein (to experience, feel, suffer)
parsley, petrify, petroleum
Petra (rock, stone)
esophagus, sarcophagus
Phagein (to eat)
emphasis, fancy, fantastic, fantasy, phantom, phase, phenomena, sycophant
Phaino, phan- (to show, make appear, bring to light)
blame, blaspheme, prophecy,
Phemi (to say, speak)
metaphor, paraphernalia, periphery, phosphate, phosphorous
Phero, phor- (to bear, carry, bring)
philanthropist, philogyny, bibliophile
Philo, phil- (love)
acrophobia, agoraphobia, claustrophobia, xenophobia
Phobia (fear)
anthem, euphony, megaphone, phone,
Phone (sound, voice)
phosphate, photograph,
Phos, phot- (light)
acropolis, cosmopolitan, metropolis, police, politics
Polis (city, state)
polygamy, polyglot, polyp, polytheism, polyglot
Poly- (much, many)
antipodes, octopus, pew, polyp, trapezoid, pew
Pous, podos (foot)