- pleiochromic anaemia
- peltandra virginica
- pennisetum americanum
- Potamogetonaceae
- Pontederiaceae
- pickerelweed family
- pipewort family
- political detainee
- pork butcher
- private treaty
- print shop
- printing shop
- perfervid
- plains pocket mouse
- phrygia
- predisposing cause
- Parrotiopsis
- Parrotia
- phytelephas
- Paris
- programmer unit
- professional golfer
- programmed operator system
- poplar bluff
- plutonic
- primrose path
- pillar of strength
- pilgrim's progress
- pisanosaurus
- pisanosaur
- pili annulati
- pilgrim father
- publius cornelius scipio
- protogenic solvent
- Pythoninae
- Pterodactylidae
- Pythonidae
- patronizing
- patronising
- puffin
- pancytopenia
- phylogeny
- phylogenesis
- pathologic process
- protein folding
- pathological process
- perennation
- prolamine
- protamine
- pheresis