- polycythemia
- parasitemia
- Polycirrus
- Porphyra
- Peridinium
- piaffe
- peridium
- polonaise
- pepino
- pjs
- pigtail
- plainsong
- panoplied
- programmed cell death
- puritanically
- photocoagulator
- pulmonary congestion
- pin cherry
- prunus pensylvanica
- prunus nigra
- pomatomus saltatrix
- pompeii
- parasellar tumour
- paperhanger
- paperer
- patentee
- periwig
- peruke
- pearl_fish
- pollyfish
- parrotfish
- polly fish
- Priacanthus arenatus
- pubescent
- port_of_spain
- photoengraving
- pudding_wife
- Pomo
- pressure aerosol
- pressure sensation
- pressure cooker
- pressure limited respirator
- pressure in the bowels
- photometry
- pelvimetry
- phencyclidine
- pseudohallucination
- phencyclidine hydrochloride
- psilocin
- psilocybin