21-letter words containing p, a, r, o
- 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.
- 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
- 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.
- sampling distribution — the distribution of a statistic based on all possible random samples that can be drawn from a given population.
- 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 multiplication — an operation used in the definition of a vector space in which the product of a scalar and a vector is a vector, the operation is distributive over the addition of both scalars and vectors, and is associative with multiplication of scalars
- 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.
- simple actor language — (language) (SAL) A minimal actor language, used for teaching in:
- single spanish burton — a tackle having a runner as well as the fall supporting the load, giving a mechanical advantage of three, neglecting friction.
- sinusoidal projection — an equal-area projection in which parallels are straight lines spaced at regular intervals, the central meridian is a straight line one-half the length of the equator, and the other meridians are curves symmetrical to the central meridian.
- snap one's fingers at — any of the terminal members of the hand, especially one other than the thumb.
- snr bandwidth product — (communications) The integral of the SNR over frequency. The SNR bandwidth product is an important limit in the capacity of a communication channel.
- social anthropologist — an anthropologist who deals with cultural and social phenomena such as kinship systems or beliefs, esp of nonliterate peoples
- social inquiry report — (in Britain) a report on a person and his or her circumstances, which may be required by a court before sentencing and is made by a probation officer or a social worker from a local authority social services department
- socialist labor party — a U.S. political party, organized in 1874, advocating the peaceful introduction of socialism.
- somatotrophic-hormone — a hormone secreted by the anterior pituitary gland, that stimulates growth in humans.
- south pacific current — an ocean current that flows E in the South Pacific Ocean parallel to the Antarctic Circumpolar Current.
- space shuttle orbiter — orbiter (def 1).
- spark ignition engine — A spark ignition engine is an engine running on the Otto cycle.
- special correspondent — a journalist who covers stories firsthand from a war zone
- special court-martial — a court-martial established to try violations of military law less serious than those tried by a general court-martial but more serious than those tried by a summary court-martial.
- spherical coordinates — Usually, spherical coordinates. any of three coordinates used to locate a point in space by the length of its radius vector and the angles this vector makes with two perpendicular polar planes.
- spin angular momentum — to make (yarn) by drawing out, twisting, and winding fibers: Pioneer women spun yarn on spinning wheels.