21-letter words containing t, a, r, n, i
- record of achievement — a statement of the personal and educational development of each pupil
- reduced circumstances — If you say that someone is living in reduced circumstances, you mean that they do not have as much money as they used to have.
- 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).
- referential integrity — (database) A collection of properties which should be possessed by data in a relational database. For example, in a database of family members, if we enter A as a spouse of B, we should also enter B as a spouse of A. Similarly, if we remove one end of the relationship we should also remove the other.
- registration document — a document giving identification details of a motor vehicle, including its manufacturer, date of registration, engine and chassis numbers, and owner's name
- rehabilitation centre — a centre or clinic where people with an alcohol or drug addiction are treated
- reinforcement therapy — a behavior modification technique in which appropriate behavior is strengthened through systematic reinforcement.
- relational data model — (database) (Or "relational model") A data model introduced by E.F. Codd in 1970, particularly well suited for business data management. In this model, data are organised in tables. The set of names of the columns is called the "schema" of the table. Here is an example table with the schema (account number, amount) and 3 lines. account number amount -------------- --------- 12343243546456 +30000.00 23149875245824 +2345.33 18479827492874 -123.25 The data can be manipulated using a relational algebra. SQL is a standard language for talking to a database built on the relational model (a "relational database").
- relaxation oscillator — a nonsinusoidal oscillator, the timing of which is controlled by the charge and discharge time constants of resistance and capacitance components
- 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.
- requirements analysis — (project) The process of reviewing a business's processes to determine the business needs and functional requirements that a system must meet.
- residual unemployment — the unemployment that remains in periods of full employment, as a result of those mentally, physically, or emotionally unfit to work
- retarded acceleration — velocity increase constrained by opposing forces such as wind resistance or braking
- reverberation chamber — a room with walls that reflect sound. It is used to make acoustic measurements and as a source of reverberant sound to be mixed with direct sound for recording or broadcasting
- 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.
- right-angled triangle — a triangle one angle of which is a right angle
- ring down the curtain — to lower the curtain at the end of a theatrical performance
- ring-around-the-rosey — a children's game in which the players sing while going around in a circle and squat when the lyrics “all fall down” are sung.
- road traffic accident — an accident involving vehicles
- rocky mountain locust — a migratory locust, Melanoplus spretus, that occurs in North America, especially the Great Plains, where swarms cause great damage to crops and other vegetation.
- rocky mountain oyster — mountain oyster.
- rolling in the aisles — (of an audience) overcome with laughter
- roman catholic church — the Christian church of which the pope, or bishop of Rome, is the supreme head.
- royal victorian order — (in Britain) an order of chivalry founded by Queen Victoria in 1896, membership of which is conferred for special services to the sovereign
- rutherford scattering — the scattering of an alpha particle through a large angle with respect to the original direction of motion of the particle, caused by an atom (Rutherford atom) with most of the mass and all of the positive electric charge concentrated at a center or nucleus.
- s-k reduction machine — An abstract machine defined by Professor David Turner to evaluate combinator expressions represented as binary graphs. Named after the two basic combinators, S and K.
- saint anthony's cross — tau cross.
- saint lawrence seaway — a series of channels, locks, and canals between Montreal and the mouth of Lake Ontario, a distance of 182 miles (293 km), enabling most deep-draft vessels to travel from the Atlantic Ocean, up the St. Lawrence River, to all the Great Lakes ports: developed jointly by the U.S. and Canada.
- saint martin's summer — mild, warm weather similar to Indian summer, occurring in November.
- saint-maur-des-fosses — a town in N central France, near Paris, on the Marne River.
- salam-weinberg theory — the electroweak theory.
- sampling distribution — the distribution of a statistic based on all possible random samples that can be drawn from a given population.
- san gabriel mountains — a mountain range in S California, N of Los Angeles. Highest peak, San Antonio Peak, 10,080 feet (3072 meters).
- san gorgonio mountain — a mountain in S California: highest peak in the San Bernardino Mountains. 11,502 feet (3506 meters).
- sanitation department — the department of local government responsible for collecting and disposing of refuse
- santa barbara islands — group of nine islands, & many islets, off the SW coast of Calif.
- santa cruz water lily — a South American aquatic plant, Victoria cruziana, of the water lily family, having floating leaves from 2–5 feet (0.6–1.5 meters) and deep pink or red flowers.
- 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.
- satisficing behaviour — the form of behaviour demonstrated by firms who seek satisfactory profits and satisfactory growth rather than maximum profits
- 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
- schlieren photography — a type of photography which records schlieren
- scintillation counter — a device for detecting and measuring radioactivity, having a crystal scintillator, a photoelectric cell sensitive to the light from scintillations, and an amplifier.
- secondary containment — Secondary containment is a system for dealing with hazardous spills.
- sedimentary sequences — Sedimentary sequences are layers of rock which are derived from weathered rocks, biogenic (= of living organisms) activity, or precipitation from solution.
- seeing/hearing things — If you say that someone is seeing or hearing things, you mean that they believe they are seeing or hearing something that is not really there.
- self-characterization — portrayal; description: the actor's characterization of a politician.
- semantic differential — a technique for measuring the connotative meaning of concepts by having an individual rate each concept on a series of graduated scales, each scale defined by a pair of polar adjectives, as good–bad or strong–weak.