21-letter words containing a, d, r
- differential geometry — the branch of mathematics that deals with the application of the principles of differential and integral calculus to the study of curves and surfaces.
- differential operator — a function, usually expressed as a polynomial, that indicates linear combinations of the derivatives of the expression on which it operates.
- differential quotient — derivative (def 6).
- differential topology — the branch of topology that studies the properties of differentiable manifolds that remain invariant under diffeomorphisms.
- differential windlass — a pair of hoisting drums of different diameter turning at the same rate, such that a pulley suspended below them on a line wound on the larger drum and unwound from the smaller drum is raised with mechanical advantage.
- differential-quotient — something that has been derived.
- direct inward dialing — (communications) (DID) A service offered by telephone companies which allows the last 3 or 4 digits of a phone number to be transmitted to the destination exchange. For example, a company could have 10 incoming lines, all with the number 234 000. If a caller dials 234 697, the call is sent to 234 000 (the company's exchange), and the digits 697 are transmitted. The company's exchange then routes the call to extension 697. This gives the impression of 1000 direct dial lines, whereas in fact there are only 10. Obviously, only 10 at a time can be used. This system is also used by fax servers. Instead of an exchange at the end of the 234 000 line, a computer running fax server software and fax modem cards uses the last three digits to identify the recipient of the fax. This allows 1000 people to have their own individual fax numbers, even though there is only one 'fax machine'.
- disassortative mating — the reproductive pairing of individuals that have traits more dissimilar than would likely be the case if mating were random (contrasted with assortative mating).
- discretionary account — an account in which the stockbroker is allowed complete control over the purchase and sale of securities on the customer's behalf.
- discriminant function — a linear function of measurements of different properties of an object or event that is used to assign the object or event to one population or another (discriminant analysis)
- disestablishmentarian — a person who favors the separation of church and state, especially the withdrawal of special rights, status, and support granted an established church by a state; an advocate of disestablishing a state church.
- disk operating system — DOS.
- display advertisement — an advertisement designed to attract attention by using devices such as conspicuous or elegant typefaces, graphics, etc
- dissociative disorder — a mental disorder, as multiple personality, characterized by sudden temporary alteration in consciousness, identity, or motor behavior.
- distant early warning — a US radar detection system to warn of missile attack
- distinctiveness ratio — the ratio of the relative frequency of some event in a given sample to that in the general population or another relevant sample
- distributed smalltalk — ["The Design and Implementation of Distributed Smalltalk", J. Bennett, SIGPLAN Notices 22(12):318-330 (Dec 1980)].
- do/did you hear (me)? — If you say 'Do you hear?' or 'Did you hear me?' to someone, you are telling them in an angry or forceful way to pay attention to what you are saying.
- double predestination — the doctrine that God has foreordained both those who will be saved and those who will be damned.
- double spanish burton — a tackle having one standing block and two running blocks, giving a mechanical advantage of five, neglecting friction.
- draft once reuse many — (jargon) (DORUM) Reusing parts of a document to produce parts of an entirely new document. The term normally refers to text documents but the practise is equally common in programming.
- drop in someone's lap — give someone the responsibility of
- drop the handkerchief — a children's game in which all the players but one stand in a circle facing inward, while that one player stealthily drops a handkerchief behind a player in the circle who must pursue and attempt to catch the one who dropped the handkerchief before the latter reaches the vacated place.
- dumfries and galloway — a region in S Scotland. 2460 sq. mi. (6371 sq. km).
- dusky seaside sparrow — a species of sparrow, Ammospiza maritima, existing in two subspecies, one (Cape Sable seaside sparrow) having dark olive-drab plumage with a lighter breast and underbelly, and the other (dusky seaside sparrow) having bold black and white markings on the breast and underbelly: the dusky seaside sparrow is almost extinct.
- dwarf japanese quince — a low, shrubby, Japanese flowering quince, Chaenomeles japonica, of the rose family, having salmon-to-orange flowers and yellow fruit.
- dynamic drive overlay — (storage, software) (DDO) Software to allow a system BIOS that does not support Logical Block Addressing to access drives larger than 528 MB. The alternatives are to update the system BIOS or install an EIDE controller card with a suitable on-board BIOS.
- easier said than done — difficult to do
- eastern daylight time — a time zone applicable to many eastern areas of the United States during the summer months, being a daylight-saving variant of Eastern Standard Time
- eastern standard time — See under standard time.
- eccles-jordan circuit — flip-flop
- electric displacement — the electric flux density when an electric field exists in free space into which a dielectric is introduced
- electromagnetic field — a field of force associated with a moving electric charge equivalent to an electric field and a magnetic field at right angles to each other and to the direction of propagation
- embarras de richesses — a superfluous abundance of options, from which one finds it difficult to select
- empire state building — New York City skyscraper
- endoplasmic reticulum — an extensive intracellular membrane system whose functions include synthesis and transport of lipids and, in regions where ribosomes are attached, of proteins
- enhanced oil recovery — any of several techniques that make it possible to recover more oil than can be obtained by natural pressure, such as the injection of fluid or gases into an oilfield to force more oil to the surface
- enharmonic modulation — a change of key achieved by regarding a note in one key as an equivalent note in another. Thus E flat in the key of A flat could be regarded as D sharp in the key of B major
- environmental studies — a university course studying the environment and related issues
- epidermolysis bullosa — type of genetic skin disorder
- every dog has his day — one's luck will come
- every nook and cranny — If you talk about every nook and cranny of a place or situation, you mean every part or every aspect of it.
- extended architecture — (storage) (XA) A CD-ROM drive specification required by Green Book CD-ROM and White Book CD-ROM formats. Drives labelled "XA ready" may require a firmware upgrade.
- extensible vax editor — (text, tool) (EVE) A DEC product implemented using DEC's Text Processing Utility (TPU).
- faculty board meeting — a meeting of the governing body of a faculty
- false memory syndrome — a psychological condition in which a person believes that he or she remembers events that have not actually occurred.
- false-memory syndrome — a psychological condition in which a person believes that he or she remembers events that have not actually occurred.
- federal reserve board — a U.S. federal banking system that is under the control of a central board of governors (Federal Reserve Board) with a central bank (Federal Reserve Bank) in each of 12 districts and that has wide powers in controlling credit and the flow of money as well as in performing other functions, as regulating and supervising its member banks.
- ferric sodium oxalate — an emerald-green, crystalline, extremely water-soluble salt, used in photography and blueprinting.
- financial underwriter — A financial underwriter is an insurance employee working in financial underwriting.