19-letter words containing o, r, a, l, c
- radioactive fallout — the settling to the ground of airborne particles ejected into the atmosphere from the earth by explosions, eruptions, forest fires, etc., especially such settling from nuclear explosions (radioactive fallout) Compare rainout.
- radiopharmaceutical — any of a number of radioactive drugs used diagnostically or therapeutically.
- raise one's hackles — one of the long, slender feathers on the neck or saddle of certain birds, as the domestic rooster, much used in making artificial flies for anglers.
- rake over the coals — a black or dark-brown combustible mineral substance consisting of carbonized vegetable matter, used as a fuel. Compare anthracite, bituminous coal, lignite.
- rancho palos verdes — a town in SW California.
- rap on the knuckles — a mild reprimand or light sentence
- rec room (or hall) — recreation room (or hall)
- recessional moraine — a moraine marking a temporary halt in the general retreat of a glacier.
- reciprocal exchange — an unincorporated association formed so that its members can participate in reciprocal insurance.
- reciprocal leveling — leveling between two widely separated points in which observations are made in both directions to eliminate the effects of atmospheric refraction and the curvature of the earth.
- reciprocity failure — a failure of the two exposure variables, light intensity and exposure time, to behave in a reciprocal fashion at very high or very low values
- reconceptualization — to form into a concept; make a concept of.
- recurrence relation — (mathematics) An equation that defines each element of a sequence in terms of one or more earlier elements. E.g. The Fibonacci sequence, X[1] = 1 X[2] = 1 X[n] = X[n-1] + X[n-2] Some recurrence relations can be converted to "closed form" where X[n] is defined purely in terms of n, without reference to earlier elements.
- reduction potential — (in a galvanic cell) the potential of the electrode at which reduction occurs.
- register allocation — (compiler, algorithm) The phase of a compiler that determines which values will be placed in registers. Register allocation may be combined with register assignment. This problem can be shown to be isomorphic to graph colouring by relating values to nodes in the graph and registers to colours. Values (nodes) which must be valid simultaneously are linked by edges and cannot be stored in the same register (coloured the same). See also register dancing and register spilling.
- regular icosahedron — an icosahedron in which each of the faces is an equilateral triangle
- relational calculus — (database) An operational methodolgy, founded on predicate calculus, dealing with descripitive expressions that are equivalent to the operations of relational algebra. Codd's reduction algorithm can convert from relational calculus to relational algebra. Two forms of the relational calculus exist: the tuple calculus and the domain calculus.
- relative complement — the set of elements contained in a given set that are not elements of another specified set.
- religious education — religion as school subject
- relocation expenses — Relocation expenses are a sum of money that a company pays to someone who moves to a new area in order to work for the company. The money is to help them pay for moving house.
- removable cartridge — a hard disk enclosed in a case that can be removed from the disk drive, having more storage than floppy disks.
- republic of ireland — John, 1838–1918, U.S. Roman Catholic clergyman and social reformer, born in Ireland: archbishop of St. Paul, Minn., 1888–1918.
- republic of vietnam — the name (from 1955–75) for South Vietnam, as an independent republic, following the division of the country in 1954 into North Vietnam and South Vietnam
- research fellowship — the position or office of someone who conducts academic research into a subject at a university, etc
- research laboratory — place for scientific experimentation
- resorcinolphthalein — fluorescein.
- reticular formation — a network of neurons in the brainstem involved in consciousness, regulation of breathing, the transmission of sensory stimuli to higher brain centers, and the constantly shifting muscular activity that supports the body against gravity.
- reticuloendothelial — pertaining to, resembling, or involving cells of the reticuloendothelial system.
- reversible reaction — a reaction that, depending on ambient conditions, can proceed in either of two directions: the production of the reaction products from the reactants, or the production of the original reactants from the formed reaction products. Compare equilibrium (def 4).
- rhetorical question — a question asked solely to produce an effect or to make an assertion and not to elicit a reply, as “What is so rare as a day in June?”.
- right circular cone — a cone whose surface is generated by lines joining a fixed point to the points of a circle, the fixed point lying on a perpendicular through the center of the circle.
- roosevelt corollary — a corollary (1904) to the Monroe Doctrine, asserting that the U.S. might intervene in the affairs of an American republic threatened with seizure or intervention by a European country.
- royal correspondent — a journalist who reports on matters relating to royalty
- saccharolactic acid — mucic acid.
- salvage archaeology — the collection of archaeological data and materials from a site in danger of imminent destruction, as from new construction or flooding.
- scale down (or up) — to reduce (or increase), often according to a fixed ratio or proportion
- screen actors guild — a labor union for motion-picture performers, founded in 1933. Abbreviation: SAG.
- secondary qualities — one of the qualities attributed by the mind to an object perceived, such as color, temperature, or taste.
- secretarial college — a college where people are trained to be secretaries
- see one's way clear — to be willing (to do something)
- seleucia tracheotis — an ancient city in SE Asia Minor, on the River Calycadnus (modern Goksu Nehri): captured by the Turks in the 13th century; site of present-day Silifke (Turkey)
- self-congratulating — the expression or feeling of uncritical satisfaction with oneself or one's own accomplishment, good fortune, etc.; complacency.
- self-congratulation — the expression or feeling of uncritical satisfaction with oneself or one's own accomplishment, good fortune, etc.; complacency.
- self-congratulatory — the expression or feeling of uncritical satisfaction with oneself or one's own accomplishment, good fortune, etc.; complacency.
- self-discrimination — an act or instance of discriminating, or of making a distinction.
- semiconductor laser — a laser in which a semiconductor is the light-emitting source, used in many medical procedures.
- senatorial courtesy — the practice in the U.S. Senate of confirming only those presidential appointees approved by both senators from the state of the appointee, or by the senior senator of the president's party.
- senatorial district — one of a fixed number of districts into which a state of the U.S. is divided, each electing one member to the state senate.
- sexual inter-course — genital contact, especially the insertion of the penis into the vagina followed by orgasm; coitus; copulation.
- sexual reproduction — reproduction involving the union of gametes.