- pervert: One who has forsaken a doctrine regarded as true for one esteemed false.
- pervious: Admitting the entrance or passage of another substance.
- pestilence: A raging epidemic.
- pestilent: Having a malign influence or effect.
- pestilential: having the nature of or breeding pestilence.
- peter: To fail or lose power, efficiency, or value.
- petrify: To convert into a substance of stony hardness and character.
- petulance: The character or condition of being impatient, capricious or petulant.
- petulant: Displaying impatience.
- pharmacopoeia: A book containing the formulas and methods of preparation of medicines for the use of druggists.
- pharmacy: The art or business of compounding and dispensing medicines.
- phenomenal: Extraordinary or marvelous.
- phenomenon: Any unusual occurrence.
- philander: To play at courtship with a woman.
- philanthropic: Benevolent.
- philanthropist: One who endeavors to help his fellow men.
- philanthropy: Active humanitarianism.
- philately: The study and collection of stamps.
- philharmonic: Fond of music.
- philogynist: One who is fond of women.
- philologist: An expert in linguistics.
- philology: The study of language in connection with history and literature.
- philosophize: To seek ultimate causes and principles.
- philosophy: The general principles, laws, or causes that furnish the rational explanation of anything.
- phlegmatic: Not easily roused to feeling or action.
- phonetic: Representing articulate sounds or speech.
- phonic: Pertaining to the nature of sound.
- phonogram: A graphic character symbolizing an articulate sound.
- phonology: The science of human vocal sounds.
- phosphorescence: The property of emitting light.
- photoelectric: Pertaining to the combined action of light and electricity.
- photometer: Any instrument for measuring the intensity of light or comparing the intensity of two lights.
- photometry: The art of measuring the intensity of light.
- physicist: A specialist in the science that treats of the phenomena associated with matter and energy.
- physics: The science that treats of the phenomena associated with matter and energy.
- physiocracy: The doctrine that land and its products are the only true wealth.
- physiognomy: The external appearance merely.
- physiography: Description of nature.
- physiology: The science of organic functions.
- physique: The physical structure or organization of a person.
- picayune: Of small value.
- piccolo: A small flute.
- piece: A loose or separated part, as distinguished from the whole or the mass.
- piecemeal: Gradually.
- pillage: Open robbery, as in war.
- pillory: A wooden framework in which an offender is fastened to boards and is exposed to public scorn.
- pincers: An instrument having two lever-handles and two jaws working on a pivot.
- pinchers: An instrument having two jaws working on a pivot.
- pinnacle: A high or topmost point, as a mountain-peak.
- pioneer: One among the first to explore a country.