19-letter words containing a, c, e, l, r, t
- national characters — (character) Characters with accents and other diacritical marks that are used in certain written languages (that are based on the Roman alphabet) but not in others, particularly not in English. A standard list is ISO Latin 1.
- national serviceman — a soldier undertaking compulsory military service
- natural catastrophe — A natural catastrophe is an unexpected event, caused by nature, such as an earthquake or flood, in which there is a lot of suffering, damage, or death.
- natural killer cell — a small killer cell that destroys virus-infected cells or tumor cells without activation by an immune system cell or antibody.
- neuropathologically — In a neuropathologic way.
- new general catalog — a catalog of star clusters, galaxies, and other non-stellar objects, published in 1888
- no-write allocation — (memory management) A cache policy where only processor reads are cached, thus avoiding the need for write-back or write-through.
- nonmaterial culture — the aggregate of values, mores, norms, etc., of a society; the ideational structure of a culture that provides the values and meanings by which it functions.
- nonplayer character — a character in a tabletop role-playing game who is controlled by the Game Master.
- north-central state — a state of N Nigeria. Capital: Kaduna. Pop: 4 438 007 (1995 est). Area: 46 053 sq km (17 781 sq miles)
- nuclear disarmament — the gradual reduction and eventual elimination of all nuclear weapons in the world
- nuclear power plant — factory that generates atomic energy
- olive-backed thrush — Swainson's thrush.
- optical double star — two stars that appear as one if not viewed through a telescope with adequate magnification, such as two stars that are separated by a great distance but are nearly in line with each other and an observer (optical double star) or those that are relatively close together and comprise a single physical system (physical double star)
- optical mark reader — (hardware) (OMR) A special scanning device that can read carefully placed pencil marks on specially designed documents. OMR is frequenty used in forms, questionnaires, and answer-sheets.
- over-centralization — the act or fact of centralizing; fact of being centralized.
- oxyacetylene burner — a blowpipe for cutting or welding metals at high temperatures
- parallactic ellipse — the apparent ellipse, as seen against the background of more distant stars, described annually by a nearby star because of the earth's orbital motion around the sun. Compare parallax (def 2).
- parallel projection — a projection from one plane to a second plane in which the lines joining points on the first plane and corresponding images are parallel.
- parthenogenetically — development of an egg without fertilization.
- particle dispersoid — A particle dispersoid is a suspension of solid particles in a gas.
- particle kinematics — Particle kinematics is the study of the movement of particles, without considering the forces that cause this movement.
- particle separation — a rule that moves the particle of a phrasal verb, thus deriving a sentence like He looked the answer up from a structure that also underlies He looked up the answer
- particle technology — Particle technology is knowledge and study which relates to particles, and is used in industry.
- particular negative — a proposition of the form “Some S is not P.” Symbol: O.
- pastoral counseling — the use of psychotherapeutic techniques by trained members of the clergy to assist parishioners who seek help for personal or emotional problems.
- paumotu archipelago — Tuamotu Archipelago.
- personal watercraft — a jet-propelled boat ridden like a motorcycle.
- phenylthiocarbamide — a crystalline, slightly water-soluble solid, C 6 H 5 NHCSNH 2 , that is either tasteless or bitter, depending upon the heredity of the taster, and is used in medical genetics and as a diagnostic.
- physical impairment — A physical impairment is a condition in which a part of a person's body is damaged or is not working properly.
- pileated woodpecker — a large, black-and-white American woodpecker, Dryocopus pileatus, having a prominent red crest.
- plastic deformation — In plastic deformation a material changes shape when a stress is applied to it and does not go back to its original state when the stress is removed.
- police headquarters — building where police are stationed
- political geography — the branch of human geography that deals with the relationship between political processes and spatial structures (regions, territories, etc)
- politically correct — marked by or adhering to a typically progressive orthodoxy on issues involving especially ethnicity, gender, sexual orientation, or ecology: The actor’s comment about unattractive women was not politically correct. The CEO feels that people who care about being politically correct are overly sensitive. Abbreviations: PC, P.C.
- post-and-rail fence — a fence constructed of upright wooden posts with horizontal timber slotted through it
- preproduction trial — a trial to test a prototype of a product before the product goes into full-scale production
- prismatic telescope — a telescope having an eyepiece at the side or top equipped with a reflecting prism, used for taking sights at steep angles.
- private first class — a soldier ranking above a private and below a corporal or specialist fourth class in the U.S. Army, and above a private and below a lance corporal in the U.S. Marine Corps.
- property speculator — a person who takes part in property speculation
- public-interest law — a branch of law that often utilizes class-action suits to protect the interest of a large group or of the public at large, as in matters relating to racial discrimination, air pollution, etc.
- quantum electronics — the application of quantum mechanics and quantum optics to the study and design of electronic devices
- 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.
- 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.
- rap on the knuckles — a mild reprimand or light sentence
- 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.
- 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.