18-letter words containing d, u, t
- population density — ratio: inhabitants to area
- population pyramid — a graph showing the distribution of a population by sex, age, etc.
- potassium chloride — a white or colorless, crystalline, water-soluble solid, KCl, used chiefly in the manufacture of fertilizers and mineral water, and as a source of other potassium compounds.
- potassium fluoride — a white, crystalline, hygroscopic, toxic powder, KF, used chiefly as an insecticide, a disinfectant, and in etching glass.
- pound the pavement — a paved road, highway, etc.
- pour cold water on — If someone pours cold water on a plan or idea, they criticize it so much that people lose their enthusiasm for it.
- predation pressure — the effect of predation upon a population, resulting in the decrease in size of that population.
- predicate calculus — predicate logic
- prefect of studies — a senior master in a Jesuit school or college
- prepare the ground — make conditions ready
- presidential suite — a suite of rooms, as in a hotel, suitable for a president or other head of state.
- product acceptance — the verification or acceptance that a manufactured item meets required specifications or standards and is usable for its purpose
- product life cycle — the four stages (introduction, growth, maturity, and decline) into one of which the sales of a product fall during its market life
- production company — an organization which produces, films, plays, television or radio programmes
- production control — the planning and supervision of manufacturing activities to ensure that goods will be produced on time at the lowest possible cost.
- production manager — a supervisor of the budget, crew and other details in the production of a film or play
- productivity bonus — an extra payment made to workers for being more productive or yielding more favourable results than normal
- programme of study — the prescribed syllabus that pupils must be taught at each key stage in the National Curriculum
- prometheus unbound — a drama in verse (1820) by Shelley.
- protective custody — detention of a person by the police solely as protection against a possible attack or reprisal by someone.
- 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.
- pseudo-anarchistic — a person who advocates or believes in anarchy or anarchism.
- pseudo-competitive — of, pertaining to, involving, or decided by competition: competitive sports; a competitive examination.
- pseudo-socialistic — of or relating to socialists or socialism.
- pseudo-symptomatic — pertaining to a symptom or symptoms.
- pseudoappendicitis — inflammation of the vermiform appendix.
- pseudointellectual — a person exhibiting intellectual pretensions that have no basis in sound scholarship.
- pseudotuberculosis — an acute, sometimes fatal disease of rodents, birds, and other animals, including humans, caused by the bacterium Yersinia (Pasteurella) pseudotuberculosis, and characterized by the formation of nodules resembling those that result from tuberculosis.
- public expenditure — spending by central government, local authorities, and public corporations
- put a bold face on — to seem bold or confident about
- 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 one in mind of — to remind (one) of
- put your foot down — If someone puts their foot down, they use their authority in order to stop something happening.
- 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
- quadratic equation — an equation containing a single variable of degree 2. Its general form is ax 2 + bx + c = 0, where x is the variable and a, b, and c are constants (a ≠ 0).
- quarry-tiled floor — a floor covered with square or diamond-shaped unglazed floor tiles
- 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
- quinacrine mustard — a nitrogen mustard derived from mepacrine and used as a stain for chromosomes
- 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.
- radiocommunication — communication by means of radio waves
- radius of gyration — the distance from an axis at which the mass of a body may be assumed to be concentrated and at which the moment of inertia will be equal to the moment of inertia of the actual mass about the axis, equal to the square root of the quotient of the moment of inertia and the mass.
- rear its ugly head — the upper part of the body in humans, joined to the trunk by the neck, containing the brain, eyes, ears, nose, and mouth.
- red cluster pepper — a tropical, woody plant, Capsicum annuum fasciculatum, having erect, very pungent, red fruit in small clusters.
- red-bellied turtle — any of several freshwater turtles of the genus Pseudemys, of the eastern and southern U.S., having red markings on the lower shell.
- red-spotted purple — any color having components of both red and blue, such as lavender, especially one deep in tone.
- reduction division — the first division of meiosis in which the number of chromosomes is reduced to half the original number.
- reduction strategy — (theory) An algorithm for deciding which redex(es) to reduce next. Different strategies have different termination properties in the presence of recursive functions or values. See string reduction, normal order reduction, applicative order reduction, parallel reduction
- redundancy payment — a sum of money given by an employer to an employee who has been made redundant: usually calculated on the basis of the employee's rate of pay and length of service