18-letter words containing p, o, u, r, i, l
- optical soundtrack — the final soundtrack on a motion picture, which appears as a band of black and white serrations along a strip of film to the left of the composite print. Light is shined through the serrations and is converted to audible sound.
- pacinian corpuscle — (sometimes lowercase) a microscopic, onionlike body consisting of layers of connective tissue wrapped around a nerve ending, located in the deep layers of skin, tendons, etc., and functioning as a sensory receptor of pressure and vibration.
- parallel computing — parallel processing
- parallel evolution — the independent development of closely corresponding adaptive features in two or more groups of organisms that occupy different but equivalent habitats, as marsupial mammals in Australia and placental mammals on other continents.
- parallel reduction — A form of applicative order reduction in which all redexes in an expression are reduced simultaneously. Variants include parallel outermost reduction and lenient reduction. See normal order reduction.
- partial evaluation — (compiler, algorithm) (Or "specialisation") An optimisation technique where the compiler evaluates some subexpressions at compile-time. For example, Partial evaluation might change the termination properties of the program if, for example, the expression (x * 0) was reduced to 0 it would terminate even if x (and thus x * 0) did not. It may be necessary to reorder an expression to partially evaluate it, e.g. f x y = (x + y) + 1 g z = f 3 z If we rewrite f: f x y = (x + 1) + y then the expression x+1 becomes a constant for the function g and we can say g z = f 3 z = (3 + 1) + z = 4 + z Partial evaluation of built-in functions applied to constant arguments is known as constant folding. See also full laziness.
- passive vocabulary — all the words, collectively, that a person can understand
- percussion flaking — a method of forming a flint tool by striking flakes from a stone core with another stone or a piece of bone or wood.
- percussion welding — a form of resistance welding in which the required pressure is provided by a hammerlike blow.
- perlocutionary act — the action of affecting someone by uttering certain words
- personal insurance — insurance on personal risk, such as car insurance, health insurance or loss of earnings insurance
- petroleum engineer — A petroleum engineer is an engineer who is involved in most stages of oil and gas field evaluation, development, and production, whose job is to maximize hydrocarbon recovery and reduce costs and environmental impact.
- piperonyl butoxide — a light-brown liquid, C 1 9 H 3 0 O 5 , used chiefly as a synergist in certain insecticides.
- population control — a policy of attempting to limit the growth in numbers of a population, esp in poor or densely populated parts of the world, by programmes of contraception or sterilization
- population figures — population totals; statistics relating to the size of populations
- population pyramid — a graph showing the distribution of a population by sex, age, etc.
- portable equipment — Portable equipment is electrical equipment that can easily be moved from one place to another while in operation or while connected to the supply.
- portal circulation — blood flow in a portal system.
- post-revolutionary — of, pertaining to, characterized by, or of the nature of a revolution, or a sudden, complete, or marked change: a revolutionary junta.
- potassium chlorate — a white or colorless, crystalline, water-soluble, poisonous solid, KClO 3 , used chiefly as an oxidizing agent in the manufacture of explosives, fireworks, matches, bleaches, and disinfectants.
- 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.
- 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.
- presuppositionless — to suppose or assume beforehand; take for granted in advance.
- process scheduling — multitasking
- 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 control — the planning and supervision of manufacturing activities to ensure that goods will be produced on time at the lowest possible cost.
- 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
- 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 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.
- purple loosestrife — an Old World plant, Lythrum salicaria, of the loosestrife family, widely naturalized in North America, growing in wet places and having spikes of reddish-purple flowers.
- pyromucic aldehyde — furfural.
- pyrosulphuric acid — a fuming liquid acid made by adding sulphur trioxide to concentrated sulphuric acid. Formula: H2S2O7
- 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
- real-time computer — a computer that can process data or information almost immediately
- 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.
- resurrection plant — a desert plant, Selaginella lepidophylla, occurring from Texas to South America, having stems that curl inward when dry.
- self-preoccupation — the state of being preoccupied.
- shop till you drop — If you shop till you drop, you do a large amount of shopping.
- simple enumeration — a procedure for arriving at empirical generalizations by haphazard accumulation of positive instances.
- sodium-vapour lamp — a type of electric lamp consisting of a glass tube containing neon and sodium vapour at low pressure through which an electric current is passed to give an orange light. They are used in street lighting
- solubility product — the maximum number of undissociated ions, of an electrolyte in a saturated solution, capable at a given temperature of remaining in equilibrium with the undissolved phase of the solution.
- special prosecutor — (formerly) an independent counsel.
- spectrofluorimeter — an instrument in which the spectrum of secondarily emitted fluorescent light is used to identify chemical compounds.
- subatomic particle — physics: