18-letter words containing a, l, g, o
- palmer archipelago — a group of islands in the South Atlantic Ocean, off the NW coast of the Antarctic Peninsula.
- parallel computing — parallel processing
- parallel importing — the importing of certain goods, esp pharmaceutical drugs, by dealers who undersell local manufacturers
- parallelogram rule — a rule for finding the resultant of two vectors by constructing a parallelogram with two adjacent sides representing the magnitudes and directions of the vectors, the diagonal through the point of intersection of the vectors representing their resultant
- parathyroid glands — any of several small oval glands usually lying near or embedded in the thyroid gland.
- passing modulation — a modulation of a temporary nature.
- pathologic anatomy — the branch of pathology dealing with the morphologic changes in tissues.
- people trafficking — the practice of bringing immigrants into a country illegally
- 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.
- personal bodyguard — a person employed to protect a particular person
- personal organizer — a small notebook with sections for personal information, as dates and addresses.
- phantasmagorically — having a fantastic or deceptive appearance, as something in a dream or created by the imagination.
- photochemical smog — air pollution containing ozone and other reactive chemical compounds formed by the action of sunlight on nitrogen oxides and hydrocarbons, especially those in automobile exhaust.
- physical geography — the branch of geography concerned with natural features and phenomena of the earth's surface, as landforms, drainage features, climates, soils, and vegetation.
- phytohemagglutinin — a lectin, obtained from the red kidney bean, that binds to the membranes of T cells and stimulates metabolic activity, cell division, etc.
- plains grasshopper — a large, destructive short-horned grasshopper, Brachystola magna, of the western U.S., marked by pinkish hind wings.
- plane trigonometry — the branch of trigonometry dealing with plane triangles.
- plate-glass window — a window that has glass which has been formed by rolling
- point d'angleterre — a bobbin lace in which the design is worked out with either a needle or bobbin.
- point-bearing pile — a pile depending on the soil or rock beneath its foot for support.
- pontifical college — the chief body of priests in ancient Rome.
- population figures — population totals; statistics relating to the size of populations
- portage la prairie — a city in S Manitoba, in S central Canada, W of Winnipeg.
- positively charged — having a positive charge
- postal storage car — a railroad car for transporting unsorted mail.
- postmaster general — the executive head of the postal system of a country.
- potential gradient — the rate of change of potential with respect to distance in the direction of greatest change.
- precedence lossage — /pre's*-dens los'*j/ A misunderstanding of operator precedence resulting in unintended grouping of arithmetic or logical operators when coding an expression. Used especially of mistakes in C code due to the nonintuitively low precedence of "&", "|", "^", "<<" and ">>". For example, the following C expression, intended to test the least significant bit of x, x & 1 == 0 is parsed as x & (1 == 0) which is always zero (false). Some lazy programmers ignore precedence and parenthesise everything. Lisp fans enjoy pointing out that this can't happen in *their* favourite language, which eschews precedence entirely, requiring one to use explicit parentheses everywhere.
- prerelease showing — a showing of a film before it goes on general release
- primate of england — a title of the archbishop of Canterbury.
- principal diagonal — a diagonal line or plane.
- programme planning — the act of creating plans or schedules, esp in relation to your occupation
- programming skills — the skills required to write a program so that data may be processed by a computer
- psychogalvanometer — a type of galvanometer for detecting and measuring psychogalvanic currents.
- psychopathological — the science or study of mental disorders.
- psychopharmacology — the branch of pharmacology dealing with the psychological effects of drugs.
- psychosociological — psychological and sociological
- publishing company — a firm which publishes books
- 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)
- racial segregation — social policy: separation of races
- ragtag and bobtail — the riffraff; rabble: The ragtag and bobtail of every nation poured into the frontier in search of gold.
- range of stability — the angle to the perpendicular through which a vessel may be heeled without losing the ability to right itself.
- refrigerated lorry — a lorry which is chilled in the back as for storing food
- reggio di calabria — a seaport in S Italy, on the Strait of Messina: almost totally destroyed by an earthquake 1908.
- reggio nell'emilia — a city in N Italy.
- regional enteritis — Crohn's disease.
- registration plate — a plate mounted on the front and back of a motor vehicle bearing the registration number
- 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
- relational algebra — (database, theory) A family of algebra with a well-founded semantics used for modelling the data stored in relational databases, and defining queries on it. The main operations of the relational algebra are the set operations (such as union, intersection, and cartesian product), selection (keeping only some lines of a table) and the projection (keeping only some columns). The relational data model describes how the data is structured.