19-letter words containing a, r, c, t, i
- puncture repair kit — set of tools for patching a bicycle tyre
- quantum electronics — the application of quantum mechanics and quantum optics to the study and design of electronic devices
- quick-change artist — a person adept at changing from one thing to another, as an entertainer who changes costumes quickly during a performance.
- radiational cooling — the cooling of the earth's surface and adjacent air, primarily at night, caused by a loss of heat due to surface emission of infrared radiation.
- 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.
- radiochromatography — chromatography in which radiolabeled substances on the chromatogram are determined quantitatively or qualitatively by measuring their radioactivity.
- radiopharmaceutical — any of a number of radioactive drugs used diagnostically or therapeutically.
- radius of curvature — the absolute value of the reciprocal of the curvature at a point on a curve.
- rayleigh scattering — the scattering of light by particles that are very small in relation to the wavelength of the light, and in which the intensity of the scattered light varies inversely with the fourth power of the wavelength.
- reactive depression — depression occurring in response to some situational stress, as loss of one's job.
- rebus sic stantibus — (of the duration of the binding force treaty) for as long as the relevant facts and circumstances remain basically the same.
- 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.
- recording secretary — an officer charged with keeping the minutes of meetings and responsible for the records.
- 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.
- 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.
- repeat prescription — A repeat prescription is a prescription for a medicine that you have taken before or that you use regularly.
- 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
- reserved occupation — in time of war, an occupation from which one will not be called up for military service
- resistance movement — a movement fighting (for freedom, etc), often secretly or illegally, against an invader in an occupied country or against the country's government, etc
- resistance training — physical training that utilizes isometric, isotonic, or isokinetic exercise to strengthen or develop the muscles.
- resonance radiation — radiation emitted by an atom or molecule, having the same frequency as that of an incident particle, as a photon, and usually involving a transition to the lowest energy level of the atom or molecule.
- resorcinolphthalein — fluorescein.
- restorative justice — a theory and method in criminal justice in which it is arranged that the victim and the community receive restitution from the offender.
- 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.
- reticulated tracery — tracery consisting in large part of a netlike arrangement of repeated geometrical figures.
- 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?”.
- rhythmic gymnastics — a form of gymnastics involving movements using hand apparatus such as balls, hoops, and ribbons
- rickettsial disease — any of several acute infectious diseases caused by ticks, mites, or body lice infected with rickettsiae. The main types include typhus, spotted fever, Q fever, trench fever, and tsutsugamushi disease
- 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.
- ring up the curtain — to begin a theatrical performance
- rocky mountain goat — a long-haired, white, antelopelike wild goat, Oreamnos americanus, of mountainous regions of western North America, having short, black horns.
- saccharolactic acid — mucic acid.
- sacrifice operative — a euphemistic term for a suicide bomber
- saint patrick's day — March 17, observed by the Irish in honor of St. Patrick, the patron saint of Ireland.
- san juan capistrano — a city in SW California: site of old Spanish mission; known for annual return of swallows, said to occur on March 19.
- sandwich generation — the generation of people still raising their children while having to care for their aging parents.
- sanitary protection — Sanitary protection is sanitary towels or tampons.
- saturation coverage — news coverage (of an event, etc) that is very thorough in order not to miss any details
- savings certificate — a certificate of deposit for a specific sum of money in a savings account, especially a deposit for a fixed term at a specified interest rate.
- scattersite housing — public housing, especially for low-income families, built throughout an urban area rather than being concentrated in a single neighborhood.
- screen actors guild — a labor union for motion-picture performers, founded in 1933. Abbreviation: SAG.