19-letter words containing a, i, l, u, r, o
- olive-backed thrush — Swainson's thrush.
- optical double star — two stars that appear as one if not viewed through a telescope with adequate magnification, such as two stars that are separated by a great distance but are nearly in line with each other and an observer (optical double star) or those that are relatively close together and comprise a single physical system (physical double star)
- oriental fruit moth — a moth, Grapholitha molesta, introduced into the U.S. from Asia, the larvae of which infest and feed on the twigs and fruits of peach, plum, and related trees.
- oscillating circuit — a circuit producing electrical oscillations.
- particular solution — a solution of a differential equation containing no arbitrary constants.
- pastoral counseling — the use of psychotherapeutic techniques by trained members of the clergy to assist parishioners who seek help for personal or emotional problems.
- paumotu archipelago — Tuamotu Archipelago.
- peroxysulfuric acid — persulfuric acid (def 1).
- perpetual adoration — uninterrupted adoration of the Blessed Sacrament.
- perpetual inventory — a form of stock control in which running records are kept of all acquisitions and disposals
- pillars of hercules — the two promontories at the E end of the Strait of Gibraltar: the Rock of Gibraltar on the European side and the Jebel Musa on the African side; according to legend, formed by Hercules
- pointe-aux-trembles — a city in S Quebec, in E Canada, N of Montreal, on the St. Lawrence.
- police headquarters — building where police are stationed
- popular sovereignty — the doctrine that sovereign power is vested in the people and that those chosen to govern, as trustees of such power, must exercise it in conformity with the general will.
- population pressure — the force exerted by a growing population upon its environment, resulting in dispersal or reduction of the population.
- preproduction trial — a trial to test a prototype of a product before the product goes into full-scale production
- production platform — offshore power station
- profitability study — a study of how much profit a company, organization, etc, makes or how profitable it is
- pseudo-biographical — of or relating to a person's life: He's gathering biographical data for his book on Milton.
- pseudo-experimental — pertaining to, derived from, or founded on experiment: an experimental science.
- pseudo-professional — following an occupation as a means of livelihood or for gain: a professional builder.
- puerperal psychosis — a mental disorder sometimes occurring in women after childbirth, characterized by deep depression, delusions of the child's death, and homicidal feelings towards the child
- quantum electronics — the application of quantum mechanics and quantum optics to the study and design of electronic devices
- queen's regulations — (in Britain and certain other Commonwealth countries when the sovereign is female) the code of conduct for members of the armed forces
- radioactive fallout — the settling to the ground of airborne particles ejected into the atmosphere from the earth by explosions, eruptions, forest fires, etc., especially such settling from nuclear explosions (radioactive fallout) Compare rainout.
- radiopharmaceutical — any of a number of radioactive drugs used diagnostically or therapeutically.
- reciprocity failure — a failure of the two exposure variables, light intensity and exposure time, to behave in a reciprocal fashion at very high or very low values
- reconceptualization — to form into a concept; make a concept of.
- recurrence relation — (mathematics) An equation that defines each element of a sequence in terms of one or more earlier elements. E.g. The Fibonacci sequence, X[1] = 1 X[2] = 1 X[n] = X[n-1] + X[n-2] Some recurrence relations can be converted to "closed form" where X[n] is defined purely in terms of n, without reference to earlier elements.
- reduction potential — (in a galvanic cell) the potential of the electrode at which reduction occurs.
- reflux oesophagitis — inflammation of the gullet caused by regurgitation of stomach acids, producing heartburn: may be associated with a hiatus hernia
- regular icosahedron — an icosahedron in which each of the faces is an equilateral triangle
- reindustrialization — the revitalization of an industry or industrial society through government aid and tax incentives, modernization of factories and machinery, etc.
- relational calculus — (database) An operational methodolgy, founded on predicate calculus, dealing with descripitive expressions that are equivalent to the operations of relational algebra. Codd's reduction algorithm can convert from relational calculus to relational algebra. Two forms of the relational calculus exist: the tuple calculus and the domain calculus.
- relational language — (language) Any kind of programming language that specifies output in terms of some property and some arguments. For example, if Tom has two brothers, Dick and Harry, a relational language will respond to the query "Who is Tom's brother?" with either Dick or Harry. Notice that unlike functional languages, relational languages do not require a unique output for each predicate/argument pair. Prolog is the best known relational language.
- religious education — religion as school subject
- republic of ireland — John, 1838–1918, U.S. Roman Catholic clergyman and social reformer, born in Ireland: archbishop of St. Paul, Minn., 1888–1918.
- republic of vietnam — the name (from 1955–75) for South Vietnam, as an independent republic, following the division of the country in 1954 into North Vietnam and South Vietnam
- respiratory failure — a condition in which the respiratory system is unable to provide an adequate supply of oxygen or to remove carbon dioxide efficiently
- reticular formation — a network of neurons in the brainstem involved in consciousness, regulation of breathing, the transmission of sensory stimuli to higher brain centers, and the constantly shifting muscular activity that supports the body against gravity.
- reticuloendothelial — pertaining to, resembling, or involving cells of the reticuloendothelial system.
- rhetorical question — a question asked solely to produce an effect or to make an assertion and not to elicit a reply, as “What is so rare as a day in June?”.
- right circular cone — a cone whose surface is generated by lines joining a fixed point to the points of a circle, the fixed point lying on a perpendicular through the center of the circle.
- sb's spiritual home — your spiritual home is the place where you feel that you belong, usually because your ideas or attitudes are the same as those of the people who live there
- screen actors guild — a labor union for motion-picture performers, founded in 1933. Abbreviation: SAG.
- sea of tranquillity — Astronomy. Mare Tranquillitatis.
- secondary qualities — one of the qualities attributed by the mind to an object perceived, such as color, temperature, or taste.
- seleucia tracheotis — an ancient city in SE Asia Minor, on the River Calycadnus (modern Goksu Nehri): captured by the Turks in the 13th century; site of present-day Silifke (Turkey)
- self-congratulating — the expression or feeling of uncritical satisfaction with oneself or one's own accomplishment, good fortune, etc.; complacency.
- self-congratulation — the expression or feeling of uncritical satisfaction with oneself or one's own accomplishment, good fortune, etc.; complacency.