17-letter words containing p, r, i, s
- opening arguments — the statements or arguments provided by lawyers at the beginning of a trial
- operation sealion — the codename for Hitler's proposed invasion (1940) of Great Britain
- operations centre — a centre where activities of a business, organization, etc, are administrated and take place
- opisthobranchiate — (zoology) Of or pertaining to the Opisthobranchiata.
- opportunistically — adhering to a policy of opportunism; practicing opportunism.
- optical astronomy — the branch of observational astronomy using telescopes to observe or photograph celestial objects in visible light.
- optical isomerism — stereoisomerism in which the isomers are identical in molecular weight and most chemical and physical properties but differ in their effect on the rotation of polarized light.
- organ-pipe cactus — a treelike or columnar cactus, Lemaireocereus marginatus, of Mexico, having a central, erect spine surrounded by spreading spines in clusters of five to eight, and funnel-shaped, brownish-purple flowers.
- organic psychosis — a severe mental illness produced by damage to the brain, as a result of poisoning, alcoholism, disease, etc
- origin of species — (On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life) a treatise (1859) by Charles Darwin setting forth his theory of evolution.
- over-compensation — a pronounced striving to neutralize and conceal a strong but unacceptable character trait by substituting for it an opposite trait.
- pacific northwest — the region of North America lying north of the Columbia River and west of the Rockies
- pair of compasses — compass (def 7)
- paleobiochemistry — the study of biochemical processes that occurred in fossil life forms.
- paleoconservative — a person advocating an older, traditional type of conservatism, especially in politics.
- paradise regained — an epic poem (1671) by John Milton.
- paradoxical sleep — REM sleep.
- parallel universe — Physics. any of a hypothetical collection of undetectable universes that are like our known universe but have branched off from our universe due to a quantum-level event. See also multiverse.
- paralysis agitans — Parkinson's disease
- paratungstic acid — an oxyacid acid of tungsten. Formula: H10W12O14
- partially sighted — unable to see properly so that even with corrective aids normal activities are prevented or seriously hindered
- particle kinetics — Particle kinetics is the study of the movement of particles and the forces that cause this movement.
- parts per million — the number of units (of a substance) present in a million units of another substance
- pascal's triangle — a triangular arrangement of the binomial coefficients of the expansion (x + y) n for positive integral values of n.
- passenger station — a station used by passengers
- passenger traffic — number of passengers
- passive restraint — a safety device, as an air bag or special seat belt, that is activated automatically to protect an automobile passenger at the moment of impact when a collision occurs.
- past life therapy — a form of hypnosis or meditation based on the belief that an individual's present problems are rooted in events that occurred before birth in this life
- pasteur institute — an organization in Paris that was founded in 1887. It does research on micro-organisms and diseases
- pate de foie gras — See under foie gras.
- paternalistically — the system, principle, or practice of managing or governing individuals, businesses, nations, etc., in the manner of a father dealing benevolently and often intrusively with his children: The employees objected to the paternalism of the old president.
- patriarchal cross — a Latin cross having a shorter crosspiece above the customary one.
- pecorino (cheese) — an Italian cheese made of sheep's milk; specif., such a cheese that is dry, sharp, and very hard
- peloponnesian war — a war between Athens and Sparta, 431–404 b.c., that resulted in the transfer of hegemony in Greece from Athens to Sparta.
- pension provision — the provision of a pension by the state or an employer
- peppermint spirit — a green or colorless alcoholic solution of the volatile oil produced by the peppermint leaf, used as a carminative and flavoring agent.
- percussion bullet — a bullet that is exploded by percussion
- pere david's deer — a medium-sized, reddish-gray deer, Elaphurus davidianus, of which stocks were obtained in Peking in 1865 and brought to parks in Europe before the remaining Chinese deer were killed in 1900: the species is sustained in captivity.
- periodic sentence — a sentence that, by leaving the completion of its main clause to the end, produces an effect of suspense, as in Unable to join the others at the dance because of my sprained ankle, I went to a movie.
- peripheral vision — all that is visible to the eye outside the central area of focus; side vision.
- pernicious anemia — Pernicious anemia is a very severe blood disease.
- perpetual spinach — a variety of spinach that keeps producing edible leaves
- persistent memory — non-volatile storage
- personal distance — personal space.
- personal equation — the tendency to personal bias that accounts for variation in interpretation or approach and for which allowance must be made.
- personality clash — friction between two people who have different personalities or points of view
- personnel carrier — a vehicle used for transporting troops
- personnel officer — a worker responsible for recruiting employees and dealing with matters relating to them
- perspicaciousness — having keen mental perception and understanding; discerning: to exhibit perspicacious judgment.
- perth and kinross — a council area of N central Scotland, corresponding mainly to the historical counties of Perthshire and Kinross-shire: part of Tayside Region from 1975 until 1996: chiefly mountainous, with agriculture, tourism, and forestry. Administrative centre: Perth. Pop: 135 990 (2003 est). Area: 5321 sq km (2019 sq miles)