18-letter words containing e, a, r, t
- cyclopean concrete — concrete containing stones larger than 6 inches (15 cm).
- cytoarchitectonics — Cytoarchitecture.
- daisywheel printer — (printer) A kind of impact printer where the characters are arranged on the ends of the spokes of a wheel (resembling the petals on a daisy). The wheel (usually made of plastic) is rotated to select the character to print and then an electrically operated hammer mechanism bends the selected spoke forward slightly, sandwiching an ink ribbon between the character and the paper, as in a typewriter. One advantage of this arrangement over that of a typewriter is that different wheels may be inserted to produce different typefaces.
- data transfer rate — (communications) (Or "throughput, data rate", "transmission rate") The amount of data transferred in one direction over a link divided by the time taken to transfer it, usually expressed in bits per second (bps), bytes per second (Bps) or baud. The link may be anything from an interface to a hard disk to a radio transmission from a satellite. Where data transfer is not continuous throughout the given time interval, the data transfer rate is thus an average rate that will be lower than the peak rate. The peak or maximum possible rate may itself be lower than the capacity of the communication channel if the channel is shared, or part of the signal is not considered as data, e.g. checksum or routing information. When applied to data rate, the multiplier prefixes "kilo-", "mega-", "giga-", etc. (and their abbreviations, "k", "M", "G", etc.) always denote powers of 1000. For example, 64 kbps is 64,000 bits per second. This contrasts with units of storage where they stand for powers of 1024, e.g. 1 KB = 1024 bytes. The other important characteristic of a channel is its latency. The bandwidth of a channel determines the data transfer rate but is a different characteristic, measured in Hertz. [Relationship?]
- datacenter manager — (job) A person who plans and directs all computer and peripheral operations, data entry, data control scheduling and quality control.
- de bruijn notation — (language) A variation of lambda notation for specifying functions using numbers instead of names to refer to formal parameters. A reference to a formal parameter is a number which gives the number of lambdas (written as \ here) between the reference and the lambda which binds the parameter. E.g. the function \ f . \ x . f x would be written \ . \ . 1 0. The 0 refers to the innermost lambda, the 1 to the next etc. The chief advantage of this notation is that it avoids the possibility of name capture and removes the need for alpha conversion.
- de-differentiation — a process by which structures or behaviors that were specialized for a specific function lose their specialization and become simplified or generalized.
- dead-letter office — an office where undeliverable letters were taken for storage
- 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
- death-valley curve — a curve on a graph showing how the capital of a new company plotted against time declines sharply as the venture capital is used up before income reaches predicted levels
- dechristianization — The act of dechristianizing; the systematic removal of Christianity or Christian elements.
- declaration of war — a formal statement made by one country to another that a state of war now exists between them
- decompartmentalize — to remove excessive compartmentalization from (an organization)
- defense calculator — IBM 701
- deferred liability — income received in advance and carried forward as a liability until the associated goods, services, or benefits are delivered
- delaware water gap — a gorge on the boundary between E Pennsylvania and NW New Jersey.
- demilitarized zone — an area from which military presence or function has been removed
- democratic deficit — any situation in which there is believed to be a lack of democratic accountability and control over the decision-making process
- 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).
- departmental store — a department store.
- departure platform — a raised area at a railway station from which passengers can board trains prior to their departing
- dependent variable — a variable in a mathematical equation or statement whose value depends on that taken on by the independent variable
- depository library — a library designated by law to receive without charge all or a selection of the official publications of a government.
- depth-first search — (algorithm) A graph search algorithm which extends the current path as far as possible before backtracking to the last choice point and trying the next alternative path. Depth-first search may fail to find a solution if it enters a cycle in the graph. This can be avoided if we never extend a path to a node which it already contains. Opposite of breadth first search. See also iterative deepening.
- 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
- descriptive clause — a relative clause that describes or supplements but is not essential in establishing the identity of the antecedent and is usually set off by commas in English. In This year, which has been dry, is bad for crops the clause which has been dry is a nonrestrictive clause.
- destruct mechanism — a mechanism that causes the destruction of a rocket or missile when activated
- detective sergeant — a police officer who investigates crime and who ranks above a detective constable but below a detective inspector
- determinate growth — growth of a plant stem that is terminated early by the formation of a bud
- devil's paintbrush — a perennial European hawkweed (Hieracium aurantiacum) with leafless flower stalks bearing a cluster of orange-red heads: now a common weed in N U.S. and Canada
- dia de los muertos — Day of the Dead.
- diamondback turtle — any edible North American terrapin of the genus Malaclemys, esp M. terrapin, occurring in brackish and tidal waters and having diamond-shaped markings on the shell: family Emydidae
- diastereoisomerism — (chemistry) Any form of stereoisomerism other than enantiomerism.
- diatomaceous earth — an unconsolidated form of diatomite
- dichloracetic acid — a highly corrosive acid. Formula: C2H2Cl2O2
- dielectric heating — the heating of a nonconducting substance caused by dielectric loss when the material is placed in a variable electric field.
- dietary supplement — a substance taken in addition to what you eat in order to promote health
- digital multimeter — (electronics) (DMM) A peice of test equipment used for measuring voltage, current, resistance, and possibly other electircal quantities and displaying the value in number form.
- digital signatures — digital signature
- 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.
- dimethyltryptamine — a hallucinogenic drug, C 12 H 16 N 2 , with an action of short duration. Abbreviation: DMT.
- diphosphoglycerate — an ester of phosphoric acid and glyceric acid that occurs in the blood and that promotes the release of hemoglobin-bound oxygen.
- diphtheria vaccine — a vaccine used to produce immunity against diphtheria
- diplomatic service — diplomatic corps
- direct examination — the first interrogation of a witness by the side that has called that witness.
- directional signal — any of four signal lights on the front left, front right, rear left, and rear right of an automotive vehicle that, when actuated by the driver, flash in pairs on the side toward which a turn is to be made.
- discharge printing — a fabric-printing method in which the material is dyed and then certain areas are discharged so as to permit the original hue or its color replacement to act as a pattern against the colored ground.
- disenfranchisement — to disfranchise.