18-letter words containing p, a, r, i
- 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.
- private enterprise — free enterprise (def 1).
- 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.
- 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 planning — the act of creating plans or schedules, esp in relation to your occupation
- programming skills — the skills required to write a program so that data may be processed by a computer
- 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.
- 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
- pyramus and thisbe — (in Greek legend) two lovers of Babylon: Pyramus, wrongly supposing Thisbe to be dead, killed himself and she, encountering him in his death throes, did the same
- 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 empiricism — (in the philosophy of William James) the doctrine that the only proper subject matter of philosophy is that which can be defined in terms of experience, and that relations are a part of experience.
- radical expression — an expression in which radical signs appear.
- rail rapid transit — a system of rail transit within an urban area that has exclusive right of way either below, above, or on the ground and so is capable of relatively high operating speed. Abbreviation: RRT.
- rape crisis centre — a place that provides support to people who have been victims of rape or other kinds of sexual abuse
- 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
- recess appointment — a person appointed to an office by the President of the United States without approval from the Senate because the Senate is in recess
- reciprocating pump — A reciprocating pump is a pump which uses a backward and forward movement to move a fluid.
- recovery operation — the process of locating and retrieving bodies, esp following an explosion or natural disaster
- registered company — a company which has officially registered its business