18-letter words containing p, r, a, u
- 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.
- preantepenultimate — third from the end.
- predation pressure — the effect of predation upon a population, resulting in the decrease in size of that population.
- predicate calculus — predicate logic
- 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.
- pressure altimeter — an aneroid barometer adapted for measuring altitude by converting the indicated atmospheric pressure to altitude according to a standard relationship.
- presumption of law — a presumption based upon a policy of law or a general rule and not upon the facts or evidence in an individual case.
- primus inter pares — (of males) first among equals.
- principal argument — the radian measure of the argument between −π and π of a complex number. Compare argument (def 8c).
- prison authorities — the people in charge of running a prison
- 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
- property insurance — insurance coverage for land and housing
- 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
- 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.
- pulp canal therapy — endodontics.
- 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.
- 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
- quarter-wave plate — a crystal thin enough to cause a phase difference of 90° between the ordinary and extraordinary rays of polarized light, thereby converting circularly polarized light into plane polarized light.
- 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
- 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.
- real-time computer — a computer that can process data or information almost immediately
- reciprocating pump — A reciprocating pump is a pump which uses a backward and forward movement to move a fluid.
- 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
- regular expression — 1. (text, operating system) (regexp, RE) One of the wild card patterns used by Perl and other languages, following Unix utilities such as grep, sed, and awk and editors such as vi and Emacs. Regular expressions use conventions similar to but more elaborate than those described under glob. A regular expression is a sequence of characters with the following meanings (in Perl, other flavours vary): An ordinary character (not one of the special characters discussed below) matches that character. A backslash (\) followed by any special character matches the special character itself. The special characters are: "." matches any character except newline; "RE*" (where RE is any regular expression and the "*" is called the "Kleene star") matches zero or more occurrences of RE. If there is any choice, the longest leftmost matching string is chosen. "^" at the beginning of an RE matches the start of a line and "$" at the end of an RE matches the end of a line. (RE) matches whatever RE matches and \N, where N is a digit, matches whatever was matched by the RE between the Nth "(" and its corresponding ")" earlier in the same RE. Many flavours use \(RE\) instead of just (RE). The concatenation of REs is a RE that matches the concatenation of the strings matched by each RE. RE1 | RE2 matches whatever RE1 or RE2 matches. \< matches the beginning of a word and \> matches the end of a word. Many flavours use "\b" instead as the special character for "word boundary". RE{M} matches M occurences of RE. RE{M,} matches M or more occurences of RE. RE{M,N} matches between M and N occurences. Other flavours use RE\{M\} etc. Perl provides several "quote-like" operators for writing REs, including the common // form and less common ??. A comprehensive survey of regexp flavours is found in Friedl 1997 (see below). 2. Any description of a pattern composed from combinations of symbols and the three operators: Concatenation - pattern A concatenated with B matches a match for A followed by a match for B. Or - pattern A-or-B matches either a match for A or a match for B. Closure - zero or more matches for a pattern. The earliest form of regular expressions (and the term itself) were invented by mathematician Stephen Cole Kleene in the mid-1950s, as a notation to easily manipulate "regular sets", formal descriptions of the behaviour of finite state machines, in regular algebra.
- repayment schedule — a document detailing the specific terms of a borrower's loan, such as monthly payment, interest rate, due dates etc
- resurrection plant — a desert plant, Selaginella lepidophylla, occurring from Texas to South America, having stems that curl inward when dry.
- room occupancy tax — Room occupancy tax is a tax that guests at a hotel have to pay in order to stay there.
- rural municipality — any lightly settled area in Canada lacking a local elected government and administered directly by a provincial government.
- russo-japanese war — the war (1904–1905) between Russia and Japan.
- salt of phosphorus — a colorless, odorless, crystalline, water-soluble solid, NaNH 4 HPO 4 ⋅4H 2 O, originally obtained from human urine: used as a blowpipe flux in testing metallic oxides.
- sampling frequency — sample rate
- scripting language — a language that is used to write scripts, or executable sections of code that automate tasks.
- sea-level pressure — the atmospheric pressure, at any elevation, reduced by formula to a value approximating the pressure at sea level.