18-letter words containing a, p, o, r
- prison authorities — the people in charge of running a prison
- prisoner's dilemma — (in game theory) a scenario in which the outcome of one person's decision is determined by the simultaneous decisions of the other participants, resulting in a bad outcome for all of them if all act in their own self-interest.
- probability theory — the theory of analyzing and making statements concerning the probability of the occurrence of uncertain events. Compare probability (def 4).
- processionary moth — a moth of the family Thaumetopoeidae, esp the oak processionary moth (Thaumetopoea processionea), the larvae of which leave the communal shelter nightly for food in a V-shaped procession
- procrustean string — (programming) A fixed-length string. If a string value is too long for the allocated space, it is truncated to fit; and if it is shorter, the empty space is padded, usually with space characters. This is an allusion to Procrustes, a legendary robber of ancient Attica. He bound his victims to a bed, and if they were shorter than the bed, he stretched their limbs until they would fit; if their limbs were longer, he lopped them off.
- product acceptance — the verification or acceptance that a manufactured item meets required specifications or standards and is usable for its purpose
- production company — an organization which produces, films, plays, television or radio programmes
- production manager — a supervisor of the budget, crew and other details in the production of a film or play
- programme of study — the prescribed syllabus that pupils must be taught at each key stage in the National Curriculum
- programme planning — the act of creating plans or schedules, esp in relation to your occupation
- programmer's cheer — (humour) "Shift to the left! Shift to the right! Pop up, push down! Byte! Byte! Byte!" [Origin?]
- programming skills — the skills required to write a program so that data may be processed by a computer
- project management — leadership of a task or programme
- projection machine — an apparatus that projects motion pictures; projector.
- promotion campaign — a campaign designed to encourage the sale of (a product) by advertising or securing financial support
- propaganda machine — the group of people, publications, etc, such as of a government, country etc, responsible for the organized dissemination of information, allegations, etc, to assist or damage the cause of a government, movement, etc
- property insurance — insurance coverage for land and housing
- proportional limit — elastic limit.
- proprietary colony — any of certain colonies, as Maryland and Pennsylvania, that were granted to an individual or group by the British crown and that were granted full rights of self-government.
- proprietary rights — rights of ownership
- protease inhibitor — a drug that inhibits the action of protease, especially any of a class of antiviral drugs that prevent the cleavage and replication of HIV proteins.
- protocol data unit — (PDU) A packet of data passed across a network. The term implies a specific layer of the OSI seven layer model and a specific protocol.
- provably difficult — The set or property of problems for which it can be proven that no polynomial-time algorithm exists, only exponential-time algorithms.
- provascular tissue — procambium.
- provincial council — (formerly) a council administering any of the New Zealand provinces
- provision merchant — a person or company in the business of retailing food and other provisions
- przewalski's horse — a wild horse, Equus caballus przevalskii, chiefly of Mongolia and Sinkiang, characterized by light yellow coloring and a stiff, upright black mane with no forelock: the only remaining breed of wild horse, it is now endangered and chiefly maintained in zoos.
- pseudo-anarchistic — a person who advocates or believes in anarchy or anarchism.
- psychogalvanometer — a type of galvanometer for detecting and measuring psychogalvanic currents.
- psychopharmacology — the branch of pharmacology dealing with the psychological effects of drugs.
- psychotherapeutics — psychotherapy.
- public corporation — a corporation, owned and operated by a government, established for the administration of certain public programs.
- pulmonary embolism — the blockage of a pulmonary artery, often by a blood clot, that stops the flow of blood to the lungs and which can result in death if untreated
- pulmonic airstream — a current of lung air set in motion by the respiratory muscles in the production of speech.
- purchasing officer — the member of staff in an organization who is responsible for buying goods or products
- put heads together — the upper part of the body in humans, joined to the trunk by the neck, containing the brain, eyes, ears, nose, and mouth.
- put out to pasture — Also called pastureland [pas-cher-land, pahs-] /ˈpæs tʃərˌlænd, ˈpɑs-/ (Show IPA). an area covered with grass or other plants used or suitable for the grazing of livestock; grassland.
- pyromucic aldehyde — furfural.
- pyrosulphuric acid — a fuming liquid acid made by adding sulphur trioxide to concentrated sulphuric acid. Formula: H2S2O7
- qattara depression — a desert basin in the Libyan Desert, in NW Egypt: lowest point is 435 feet (133 meters) below sea level. 6950 sq. mi. (18,000 sq. km).
- quartz-iodine lamp — a type of tungsten-halogen lamp containing small amounts of iodine and having a quartz envelope, operating at high temperature and producing an intense light for use in car headlamps, etc
- rabbit-proof fence — a fence through which rabbits are unable to pass
- radiation exposure — exposure to radiant energy or to the particles emitted in the transfer of radiant energy, esp the particles and gamma rays emitted in nuclear decay; exposure to radioactive substances
- radiation pressure — the pressure exerted on a surface by electromagnetic radiation or by sound waves.
- radical expression — an expression in which radical signs appear.
- raman spectroscopy — a form of spectroscopy which uses the Raman effect for studying molecules
- rapid eye movement — rapidly shifting, continuous movements of the eyes beneath closed lids during the stage of sleep characterized by dreaming.
- rational operation — any of the mathematical operations of addition, subtraction, multiplication, and division.
- reactive component — the component in an alternating-current circuit that does not contribute power because it is 90° out of phase with the voltage or current.
- real-time computer — a computer that can process data or information almost immediately