18-letter words containing a, s, p, o
- pseudointellectual — a person exhibiting intellectual pretensions that have no basis in sound scholarship.
- 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
- psychotherapeutics — psychotherapy.
- ptomaine poisoning — (erroneously) food poisoning thought to be caused by ptomaine.
- 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.
- 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.
- pygmy hippopotamus — a small hippopotamus, Choeropsis liberiensis, of forests and swamps in western Africa.
- pyrosulphuric acid — a fuming liquid acid made by adding sulphur trioxide to concentrated sulphuric acid. Formula: H2S2O7
- qattara depression — a desert basin in the Libyan Desert, in NW Egypt: lowest point is 435 feet (133 meters) below sea level. 6950 sq. mi. (18,000 sq. km).
- 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.
- radical expression — an expression in which radical signs appear.
- raman spectroscopy — a form of spectroscopy which uses the Raman effect for studying molecules
- recess appointment — a person appointed to an office by the President of the United States without approval from the Senate because the Senate is in recess
- registered company — a company which has officially registered its business
- 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.
- reinforced plastic — plastic with fibrous matter, such as carbon fibre, embedded in it to confer additional strength
- reporters' gallery — an area in parliament reserved for journalists and reporters
- reprocessing plant — a plant where materials are treated in order to make them reusable
- respiratory arrest — cessation of breathing
- respiratory system — the system by which oxygen is taken into the body and an exchange of oxygen and carbon dioxide takes place; in mammals the system includes the nasal passages, pharynx, trachea, bronchi, and lungs.
- resurrection plant — a desert plant, Selaginella lepidophylla, occurring from Texas to South America, having stems that curl inward when dry.
- rhodes scholarship — one of a number of scholarships at Oxford University, established by the will of Cecil Rhodes, for selected students (Rhodes scholars) from the British Commonwealth and the United States.
- russo-japanese war — the war (1904–1905) between Russia and Japan.
- safety-deposit box — a lockable metal box or drawer, especially in a bank vault, used for safely storing valuable papers, jewelry, etc.
- 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.
- scholarship holder — a person who, because of academic merit, receives financial aid for their studies
- scissors-and-paste — designating or of a piece of writing that has been assembled from a variety of sources rather than by original research, often in a hasty or uninspired way
- seafloor spreading — a process in which new ocean floor is created as molten material from the earth's mantle rises in margins between plates or ridges and spreads out.
- seasonal promotion — Seasonal promotions are items marketed to customers at the appropriate time of year, such as coats in the winter and bathing suits in the summer.
- secondary syphilis — the second stage of syphilis, characterized by eruptions of the skin and mucous membrane.
- segmental phonemes — phonemes consisting of sound segments; hence, the vowel, consonant, and semivowel sounds of a language
- self-contemplation — the act or process of thinking about oneself or one's values, beliefs, behavior, etc.
- self-preoccupation — the state of being preoccupied.
- sell someone a pup — to swindle someone by selling him something worthless
- separation anxiety — the normal fear and apprehension expressed by infants when removed from their mothers or approached by strangers.
- september holidays — a period of time in September when people do not have to go to school, college or work
- septic sore throat — an acute, toxic, streptococcus infection of the throat producing fever, tonsillitis, and other serious effects.
- shape-note singing — a traditional style of a capella singing using shape-note notation.
- shatterproof glass — glass designed to resist shattering
- shipping container — a large, strong container, usually of metal, used to store goods in during shipment