18-letter words containing r, h, o, d, a
- circular dichroism — selective absorption of one of the two possible circular polarizations of light.
- closed scholarship — a scholarship for which only certain people, such as those from a particular school or with a particular surname, are eligible
- coast rhododendron — a rhododendron, Rhododendron macrophyllum, of western North America, having large clusters of rose-purple flowers spotted with brown: the state flower of Washington.
- commander in chief — Also, Commander in Chief. the supreme commander of the armed forces of a nation or, sometimes, of several allied nations: The president is the Commander in Chief of the U.S. Army, Navy, and Air Force.
- commander-in-chief — A commander-in-chief is a senior officer who is in charge of all the forces in a particular area.
- comparative method — a body of procedures and criteria used by linguists to determine whether and how two or more languages are related and to reconstruct forms of their hypothetical parent language.
- connected subgraph — (mathematics) A connected graph consisting of a subset of the nodes and edges of some other graph.
- considered harmful — (programming, humour) A type of phrase based on the title of Edsger W. Dijkstra's famous note in the March 1968 Communications of the ACM, "Goto Statement Considered Harmful", which fired the first salvo in the structured programming wars. Amusingly, the ACM considered the resulting acrimony sufficiently harmful that it will (by policy) no longer print articles taking so assertive a position against a coding practice. In the ensuing decades, a large number of both serious papers and parodies bore titles of the form "X considered Y". The structured-programming wars eventually blew over with the realisation that both sides were wrong, but use of such titles has remained as a persistent minor in-joke.
- cot death syndrome — the unexplained sudden death of an infant during sleep
- deanthropomorphism — the ridding of philosophy or religion of anthropomorphic beliefs and doctrines.
- dear john (letter) — a letter from one's fiancée or girlfriend breaking off an engagement or love affair, or from one's wife asking for a divorce
- decachlorobiphenyl — (organic compound) The fully chlorinated polychlorinated biphenyl containing ten chlorine atoms.
- dechristianization — The act of dechristianizing; the systematic removal of Christianity or Christian elements.
- demorgan's theorem — (logic) A logical theorem which states that the complement of a conjunction is the disjunction of the complements or vice versa. In symbols: not (x and y) = (not x) or (not y) not (x or y) = (not x) and (not y) E.g. if it is not the case that I am tall and thin then I am either short or fat (or both). The theorem can be extended to combinations of more than two terms in the obvious way. The same laws also apply to sets, replacing logical complement with set complement, conjunction ("and") with set intersection, and disjunction ("or") with set union. A (C) programmer might use this to re-write if (!foo && !bar) ... as if (!(foo || bar)) ... thus saving one operator application (though an optimising compiler should do the same, leaving the programmer free to use whichever form seemed clearest).
- dermot macmurrough — ?1110–71, king of Leinster, who, by enlisting the support of the English to win back his kingdom, was responsible for the English conquest of Ireland
- determinate growth — growth of a plant stem that is terminated early by the formation of a bud
- diatomaceous earth — an unconsolidated form of diatomite
- dichloracetic acid — a highly corrosive acid. Formula: C2H2Cl2O2
- digital switchover — the process of changing the method of transmitting television from analogue to digital format
- dihydrotachysterol — a white, crystalline, water-insoluble sterol, C 28 H 46 O, derived from ergosterol: used chiefly in the treatment of hypoparathyroidism.
- diphosphoglycerate — an ester of phosphoric acid and glyceric acid that occurs in the blood and that promotes the release of hemoglobin-bound oxygen.
- division algorithm — the theorem that an integer can be written as the sum of the product of two integers, one a given positive integer, added to a positive integer smaller than the given positive integer. Compare Euclidean algorithm.
- dodecadodecahedral — Having the form of a dodecadodecahedron.
- dodecadodecahedron — (geometry) A nonconvex polyhedron with twenty-four faces, thirty vertices, and sixty edges.
- drinking chocolate — sweetened cocoa powder
- drug on the market — Pharmacology. a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being.
- dry-powder inhaler — A dry-powder inhaler is a device that delivers medication to the lungs in the form of a dry powder.
- each and every one — all
- electrocardiograph — A machine used for electrocardiography.
- euclid's algorithm — (algorithm) (Or "Euclidean Algorithm") An algorithm for finding the greatest common divisor (GCD) of two numbers. It relies on the identity gcd(a, b) = gcd(a-b, b) To find the GCD of two numbers by this algorithm, repeatedly replace the larger by subtracting the smaller from it until the two numbers are equal. E.g. 132, 168 -> 132, 36 -> 96, 36 -> 60, 36 -> 24, 36 -> 24, 12 -> 12, 12 so the GCD of 132 and 168 is 12. This algorithm requires only subtraction and comparison operations but can take a number of steps proportional to the difference between the initial numbers (e.g. gcd(1, 1001) will take 1000 steps).
- every now and then — from time to time; occasionally
- fall to the ground — (of a plan, theory, etc) to be rendered invalid, esp because of lack of necessary information
- feast of orthodoxy — a solemn festival held on the first Sunday of Lent (Orthodoxy Sunday) commemorating the restoration of the use of icons in the church (a.d. 842) and the triumph over all heresies.
- feldenkrais method — a system of gentle movements that promote flexibility, coordination, and self-awareness
- fourth commandment — “Remember the sabbath day, to keep it holy”: fourth of the Ten Commandments.
- from hand to mouth — the terminal, prehensile part of the upper limb in humans and other primates, consisting of the wrist, metacarpal area, fingers, and thumb.
- green-backed heron — a small, American heron, Butorides striatus, having glossy green wings.
- harnessed antelope — any African antelope of the genus Tragelaphus, especially the bushbuck, having the body marked with white stripes and spots that resemble a harness, and, in the male, long, gently spiraling horns.
- haud your wheesht! — be silent! hush!
- have words with sb — If one person has words with another, or if two or more people have words, they have a serious discussion or argument, especially because one has complained about the other's behaviour.
- head and shoulders — If you say that someone or something stands head and shoulders above other people or things, you mean that they are a lot better than them.
- hearts and flowers — maudlin sentimentality: The play is a period piece, full of innocence abused and hearts and flowers.
- hermaphrodite brig — a two-masted sailing vessel, square-rigged on the foremast and fore-and-aft-rigged on the mainmast.
- heteroscedasticity — (statistics) The property of a series of random variables of 'not' every variable having the same finite variance.
- heteroskedasticity — Alternative spelling of heteroscedasticity.
- hexaphosphorylated — (biochemistry) phosphorylated with six units of phosphoric acid.
- higher-order macro — A means of expressing certain higher-order functions in a first order language. Proposed by Phil Wadler. Higher-order macros cannot be recursive at the top level but they may contain recursive definitions. E.g. See partial evaluation.
- hold a reservation — If a hotel holds a reservation, it keeps a room for someone, and does not give it to someone else.
- honorable ordinary — any of the ordinaries believed to be among those that are oldest or that were the source of the other ordinaries, as the chief, pale, fess, bend, chevron, cross, and saltire.
- honour moderations — (at Oxford University) the first public examination, in which candidates are placed into one of three classes of honours