18-letter words containing t, r
- 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).
- dendrochronologist — One who carries out dendrochronology.
- 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.
- derestriction sign — a circular white sign with a black diagonal band signifying the lifting of any other speed restriction
- 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
- developing country — a nonindustrialized poor country that is seeking to develop its resources by industrialization
- development period — a length of time during which a company grows
- 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
- dictionary catalog — a library catalog having all its entries, including authors, titles, subjects, etc., in one general alphabetical sequence.
- 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
- diethylstilbestrol — a nonsteroidal synthetic estrogen, C 18 H 20 O 2 , used in medicine chiefly in the treatment of menopausal symptoms and in animal feeds for chemical caponization: formerly used during pregnancy for the prevention of miscarriage but discontinued owing to its association with an increased risk of vaginal and cervical cancers in women having had fetal exposure. Abbreviation: DES.
- 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.
- disorderly conduct — any of various petty misdemeanors, generally including nuisances, breaches of the peace, offensive or immoral conduct in public, etc.
- dispersible tablet — A dispersible tablet is a tablet that disintegrates in water or other liquid.
- display postscript — An extended form of PostScript permitting its interactive use with bitmap displays.
- disproportionality — not in proportion; disproportionate.
- disproportionately — not proportionate; out of proportion, as in size or number.
- disproportionation — the simultaneous oxidation and reduction of a substance reacting with itself, thereby forming two dissimilar molecules, as 2C 2 H 4 →C 2 H 6 +C 2 H 2 .
- distracted driving — driving a vehicle while engaging in an activity that has the potential to distract the driver from the task of driving: Bans on cell phone use in cars will help to reduce the dangers of distracted driving.