pedophile, pedometer, pedology

paleontologist, paleolithic, paleontology,

panacea, pan-Africanism, pan-Arabism, pandemic, pandemonium, Pandora, panegyric, pan-European, Pangaea, pan-German, Panglossian, Panhellenic, pan-Islamic, panoply

parasol, parapet, parable, paracentesis, parachronism, paradigm, paradox, paraesthesia, paragon, paragraph, paralanguage, paralegal

perform, perception, perspective

pericardium, perihelion, perimeter, perinatal, perineum, period, periodontal, periorbital, periosteum, peripatetic, peripeteia, periphery, periphrasis, Periscian, periscope

petrochemical, petrology, petrodollar, petroleum

phenobarbital, phenol, phenotype, phenyl

phlebitis, phlebotomy, phlebotomist, phlebothrombosis, phlebogram, phlebotomize

photocopy, photo-electric, photogenic, photograph, photography, photogravure, photoinduction, photojournalism, photometer, photon, photophobia, photosphere, photostat, photosynthesis, phototropism, photovoltaic

frenetic, phrenic, phrenology, schizophrenia

phyletic, phylogenesis, phylum

phytoplankton, xerophyte, phytochemical

picosecond, picometer

piezoelectric, piezometer

Pithecanthropus, pithecology

plagioclase, plagiocephaly

planing, planimetric, planish, planogram, planography

pleomorphic, pleonastic, pleiotropic, pleiotropy

pleural, pleurisy

pluripotent, pluripotency, plurilateral

pneumatosis, pneumatocele, pneumatology, pneumatic, pneumatics

pneumonic, pneumothorax, pulmonary

polymer, monopolylogue, plus, polyamorous, polycentric, polychrome, polyclinic, polydactylism, polyethnic, polyethylene, polygamy, polygenesis, polygenetic, polygenic

postdate, posterior, posterity, postern, post-glacial, post-graduate, post-impressionism, postlude, post-millennial, post-modern

apprehend, apprehension, apprise, comprehend, comprehension, comprehensive, comprise, emprise, enterprise, impresario, misprision, pre-adamite, pre-admission

presbyopia, presbyter, Presbyterian, presbytery

prohibit, provide, procure, proconsul, pronoun, problem

proterozoic, proterosoma

protist, protocol, proto-language, proton, protoplanet, protoplasm, protostar, prototype, Protozoa, protozoic

psammoma, psammophilous, psammous, psammophile