21-letter words containing a, p, e, r
- psychopharmacotherapy — the use of psychoactive drugs in the symptomatic treatment or control of mental disorders or psychiatric disease.
- public address system — loudspeaker
- public health service — the agency that is responsible for the health of the general public
- public-address system — a combination of electronic devices that makes sound audible via loudspeakers to many people, as in an auditorium or out of doors.
- pulse height analyser — a multichannel analyser that sorts pulses into selected amplitude ranges
- pulse height analyzer — an instrument that records or counts an electrical pulse if its amplitude falls within specified limits: used in nuclear physics research for the determination of energy spectra of nuclear radiations
- purchasing department — the group of staff within an organization that is responsible for buying goods or products
- pure imaginary number — a complex number of the form iy where y is a real number and i = .
- put in the hard yards — to make a great effort to achieve an end
- put sb in their place — If you put someone in their place, you show them that they are less important or clever than they think they are.
- put sb out to pasture — If you say that someone is being put out to pasture, you mean they are no longer being employed because they are considered to be too old or no longer useful.
- pyrenean mountain dog — a large heavily built dog of an ancient breed originally used to protect sheep from wild animals: it has a long thick white coat with a dense ruff
- quality point average — grade point average.
- quantum teleportation — a hypothetical technique to instantly transfer properties from one quantum system to another without contact, or to transfer a quantum state to an arbitrarily distant location.
- ralph roister doister — a play (1553?) by Nicholas Udall: the earliest known English comedy.
- rap over the knuckles — to reprimand
- reading comprehension — a text that students use to help them improve their reading skills, by reading it and answering questions relating to the text. Sometimes used as a test or examination of reading skills. A reading comprehension can be in the student's own or another language
- real operating system — (operating system, abuse) The sort the speaker is used to. People from the BSDophilic academic community are likely to issue comments like "System V? Why don't you use a *real* operating system?", people from the commercial/industrial Unix sector are known to complain "BSD? Why don't you use a *real* operating system?", and people from IBM object "Unix? Why don't you use a *real* operating system?" See holy wars, religious issues, proprietary, Get a real computer!.
- real-estate developer — a person who buys and develops houses, buildings, and land in order to sell them and make a profit from them
- reciprocal inhibition — the theory that the pairing of an anxiety-provoking stimulus with anxiety-reducing reactions will weaken the association between the stimulus and the anxiety.
- recompression chamber — hyperbaric chamber.
- reconnaissance patrol — a patrol made by soldiers in order to obtain military information about a particular place
- rectangular hyperbola — a hyperbola with perpendicular asymptotes
- red-headed woodpecker — a black and white North American woodpecker, Melanerpes erythrocephalus, having a red head and neck.
- redevelopment company — a private corporation or a public agency that stimulates the improvement of land, as through a building project subject to certain designs and controls, by financing, selling, or leasing such real estate to interested buyers or lessees.
- redlegged grasshopper — a migratory grasshopper, Melanoplus femur-rubrum, of the southwestern and midwestern U.S., having reddish skin on the underside of the hind legs: an agricultural pest.
- redwood national park — a national park in N California: redwood forest with some of the world's tallest trees. 172 sq. mi. (445 sq. km).
- reinforcement therapy — a behavior modification technique in which appropriate behavior is strengthened through systematic reinforcement.
- relative permeability — the ratio of the permeability of a medium to that of free space
- relative permittivity — Electricity. the ratio of the flux density produced by an electric field in a given dielectric to the flux density produced by that field in a vacuum.
- remote procedure call — (networking, programming) (RPC) A protocol which allows a program running on one host to cause code to be executed on another host without the programmer needing to explicitly code for this. RPC is an easy and popular paradigm for implementing the client-server model of distributed computing. An RPC is initiated by the caller (client) sending request message to a remote system (the server) to execute a certain procedure using arguments supplied. A result message is returned to the caller. There are many variations and subtleties in various implementations, resulting in a variety of different (incompatible) RPC protocols.
- repatriation expenses — Repatriation expenses are the costs involved in transporting a claimant or their body back to their own country after they have been injured or killed in a foreign country.
- replacement algorithm — The method used to determine which entry in an associative cache to flush to main memory when it is desired to cache a new block of data. The "least recently used" algorithm flushed the block which has not been accessed for the longest time. A random replacement algorithm picks any block with equal probability.
- residual unemployment — the unemployment that remains in periods of full employment, as a result of those mentally, physically, or emotionally unfit to work
- reverse polish syntax — postfix notation
- reverse transcriptase — a retrovirus enzyme that synthesizes DNA from viral RNA, the reverse of the usual DNA-to-RNA replication: used in genetic engineering to clone genes from RNA strands.
- rio de la plata river — Rí·o de la [ree-aw th e lah] /ˈri ɔ ðɛ lɑ/ (Show IPA) an estuary on the SE coast of South America between Argentina and Uruguay, formed by the Uruguay and Paraná rivers, about 185 miles (290 km) long.
- rob peter to pay paul — to take something from (someone) by unlawful force or threat of violence; steal from.
- roodepoort-maraisburg — a city in S Transvaal, in the NE Republic of South Africa.
- sanitation department — the department of local government responsible for collecting and disposing of refuse
- sao bernardo do campo — a city in SE Brazil, SE of São Paulo.
- sao jose do rio preto — a city in SE Brazil, NW of São Paulo.
- sao tome and principe — Democratic Republic of, a republic in W Africa, comprising the islands of São Tomé and Príncipe, in the Gulf of Guinea, N of the equator: a former overseas province of Portugal; gained independence in 1975. 372 sq. mi. (964 sq. km). Capital: São Tomé.
- saponification number — the number of milligrams of potassium hydroxide required to saponify one gram of a given ester, especially a glyceride.
- scalar triple product — the volume of the parallelepiped defined by three given vectors, u, v, and w, usually represented as u·v 1 (v×w), [ uvw ], or (uvw), where × denotes a cross product and · denotes an inner product.
- schlieren photography — a type of photography which records schlieren
- scorched earth policy — a military practice of devastating the property and agriculture of an area before abandoning it to an advancing enemy.
- scorched-earth policy — a military practice of devastating the property and agriculture of an area before abandoning it to an advancing enemy.
- sequoia national park — a national park in central California: giant sequoia trees. 604 sq. mi. (1565 sq. km).
- sheppard's correction — a method of correcting the bias in standard deviations and higher moments of distributions that arises from grouping values of the variable.