18-letter words containing a, l, u
- 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-socialistic — of or relating to socialists or socialism.
- pseudointellectual — a person exhibiting intellectual pretensions that have no basis in sound scholarship.
- public corporation — a corporation, owned and operated by a government, established for the administration of certain public programs.
- public examination — an examination, such as a GCSE exam, that is set by a central examining board
- publicity campaign — an effort to convey information to the public
- publishing company — a firm which publishes books
- pull one's head in — the upper part of the body in humans, joined to the trunk by the neck, containing the brain, eyes, ears, nose, and mouth.
- 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.
- put a bold face on — to seem bold or confident about
- put the clock back — to regress
- pyromucic aldehyde — furfural.
- pyrosulphuric acid — a fuming liquid acid made by adding sulphur trioxide to concentrated sulphuric acid. Formula: H2S2O7
- quality controller — a person responsible for checking that the goods or services produced by an organization are of an acceptable standard
- quality of service — (communications, networking) (QoS) The performance properties of a network service, possibly including throughput, transit delay, priority. Some protocols allow packets or streams to include QoS requirements.
- quarry-tiled floor — a floor covered with square or diamond-shaped unglazed floor tiles
- 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.
- quarterlife crisis — a crisis that may be experienced in one's twenties, involving anxiety over the direction and quality of one's life
- 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
- quasi-metaphysical — pertaining to or of the nature of metaphysics.
- quevedo y villegas — Francisco Gómez de. 1580–1645, Spanish poet and writer, noted for his satires and the picaresque novel La historia de la vida del Buscón (1626)
- real-time computer — a computer that can process data or information almost immediately
- 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.
- 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.
- regular hexahedron — a solid cube with six square faces
- regular tertiaries — of the third order, rank, stage, formation, etc.; third.
- relative frequency — the ratio of the number of times an event occurs to the number of occasions on which it might occur in the same period.
- repayment schedule — a document detailing the specific terms of a borrower's loan, such as monthly payment, interest rate, due dates etc
- residual magnetism — remanence.
- restrictive clause — a relative clause that identifies the antecedent and that is usually not set off by commas in English. In The year that just ended was bad for crops, the clause that just ended is a restrictive clause.
- resurrection plant — a desert plant, Selaginella lepidophylla, occurring from Texas to South America, having stems that curl inward when dry.
- revolutionary wars — American Revolution.
- rheims-douay bible — Douay Bible.
- rule of engagement — a directive issued by a military authority controlling the use and degree of force, especially specifying circumstances and limitations for engaging in combat.
- run in sb's family — If a characteristic runs in someone's family, it often occurs in members of that family, in different generations.
- running martingale — martingale (def 2).
- rural municipality — any lightly settled area in Canada lacking a local elected government and administered directly by a provincial government.
- russian revolution — Also called February Revolution. the uprising in Russia in March, 1917 (February Old Style), in which the Czarist government collapsed and a provisional government was established.
- safety regulations — regulations or rules that are put in place to ensure a product, event, etc, is safe and not dangerous
- 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 equipment — Sampling equipment is equipment which is used to remove small amounts of something for analysis and monitoring.
- sampling frequency — sample rate
- sao caetano do sul — a city in SE Brazil, SE of São Paulo.
- saturated solution — A saturated solution is a solution in which there is so much solute that if there was any more, it would not dissolve.
- sault sainte marie — the rapids of the St. Marys River, between NE Michigan and Ontario, Canada.
- schwarz inequality — Also called Cauchy's inequality. the theorem that the inner product of two vectors is less than or equal to the product of the magnitudes of the vectors.