digraph (n.) Look up digraph at Dictionary.com
1788, in linguistics, from Greek di- "twice" (see di- (1)) + -graph "something written," from Greek graphe "writing," from graphein "to write, express by written characters," earlier "to draw, represent by lines drawn" (see -graphy). In mathematics, from 1955, a contraction of directed graph.
digress (v.) Look up digress at Dictionary.com
1520s, from Latin digressus, past participle of digredi "to go aside, depart" (see digression), or perhaps a back-formation from digression. Related: Digressed; digressing.
digression (n.) Look up digression at Dictionary.com
late 14c., from Latin digressionem (nominative digressio) "a going away, departing," noun of action from past participle stem of digredi "to deviate," from dis- "apart, aside" (see dis-) + gradi "to step, go" (see grade (n.)).
digs (n.) Look up digs at Dictionary.com
"lodgings," slang attested from 1893, from dig.
dike (n.) Look up dike at Dictionary.com
Old English dic "trench, ditch; an earthwork with a trench; moat," from Proto-Germanic *dik- (source also of Old Norse diki "ditch, fishpond," Old Frisian dik "mound, dam," Middle Dutch dijc "mound, dam, pool," Dutch dijk "dam," German Deich "embankment"), from PIE root *dhigw- "to pierce; to fix, fasten" (source also of Sanskrit dehi- "wall," Old Persian dida "wall, stronghold, fortress," Persian diz).

At first "an excavation," later (late 15c.) applied to the resulting earth mound; a sense development paralleled by cognate forms in many other languages. This is the northern variant of the word that in the south of England yielded ditch (n.).
diktat (n.) Look up diktat at Dictionary.com
1933, from German Diktat "dictate."
dilapidate (v.) Look up dilapidate at Dictionary.com
1560s, "to bring a building to ruin," from Latin dilapidatus, past participle of dilapidare "to squander, waste," originally "to throw stones, scatter like stones;" see dilapidation. Perhaps the English word is a back-formation from dilapidation.
dilapidated (adj.) Look up dilapidated at Dictionary.com
"in ruins, broken down," 1806, past participle adjective from dilapidate.
dilapidation (n.) Look up dilapidation at Dictionary.com
early 15c., from Late Latin dilapidationem (nominative dilapidatio) "a squandering," noun of action from past participle stem of Latin dilapidare "throw away, squander, waste," literally "pelt with stones" (thus "ruin, destroy") or else "scatter like stones," from dis- "asunder" (see dis-) + lapidare "throw stones at," from lapis (genitive lapidis) "stone" (see lapideous). "Taken in Eng. in a more literal sense than was usual in Latin" [OED].
dilatation (n.) Look up dilatation at Dictionary.com
c. 1400, from Old French dilatation, from Late Latin dilatationem (nominative dilatatio) "a widening," from past participle stem of Latin dilatare (see dilate).
dilate (v.) Look up dilate at Dictionary.com
late 14c., from Old French dilater, from Late Latin dilatare "make wider, enlarge," from dis- "apart" (see dis-) + latus "wide" (see latitude). Related: Dilated; dilating.
dilation (n.) Look up dilation at Dictionary.com
1590s, formed from dilate on the mistaken assumption that the -ate in that word was the Latin verbal suffix (it is instead part of the stem); the proper form, dilatation, is older (c. 1400).
dilatory (adj.) Look up dilatory at Dictionary.com
late 15c., from Late Latin dilatorius, from dilator "procrastinator," from dilatus, serving as past participle of differe "delay" (see defer).
dildo (n.) Look up dildo at Dictionary.com
1590s, perhaps a corruption of Italian deletto "delight," from Latin dilectio, noun of action from diligere "to esteem highly, to love" (see diligence). Or (less likely) of English diddle. "Curse Eunuke dilldo, senceless counterfet" ["Choise of Valentines or the Merie Ballad of Nash his Dildo," T. Nashe, c. 1593] A classical Latin word for one was fascinum (see fascinate). In later English sometimes a French word, godemiche, was used (1879).
dilemma (n.) Look up dilemma at Dictionary.com
1520s, from Late Latin dilemma, from Greek dilemma "double proposition," a technical term in rhetoric, from di- "two" + lemma "premise, anything received or taken," from root of lambanein "to take" (see analemma). It should be used only of situations where someone is forced to choose between two alternatives, both unfavorable to him. But even logicians disagree on whether certain situations are dilemmas or mere syllogisms.
dilettante (n.) Look up dilettante at Dictionary.com
1733, borrowing of Italian dilettante "lover of music or painting," from dilettare "to delight," from Latin delectare (see delight (n.)). Originally without negative connotation, "devoted amateur," the pejorative sense emerged late 18c. by contrast with professional.
diligence (n.) Look up diligence at Dictionary.com
mid-14c., from Old French diligence "attention, care; haste, speed," from Latin diligentia "attentiveness, carefulness," from diligentem (nominative diligens) "attentive, assiduous, careful," originally present participle of diligere "single out, value highly, esteem, prize, love; aspire to, be content with, appreciate," originally "to pick out, select," from dis- "apart" (see dis-) + legere "choose, gather" (see lecture (n.)).

Sense evolved from "love" through "attentiveness" to "carefulness" to "steady effort." From the secondary French sense comes the old useage of diligence for "public stage coach" (1742; dilly for short), from a French shortening of carrosse de diligence.
diligent (adj.) Look up diligent at Dictionary.com
mid-14c., from Old French diligent (14c.), from Latin diligentem "attentive, assiduous" (see diligence). Related: Diligently.
dill (n.) Look up dill at Dictionary.com
Old English dile "dill, anise," a Germanic word of unknown origin (cognates: Old Saxon dilli, Middle Dutch and Dutch dille, Swedish dill, German Dill).
dilly (n.) Look up dilly at Dictionary.com
"delightful or excellent person or thing" (often used ironically), 1935, American English, from an earlier adjective (1909), perhaps from the first syllable of delightful or delicious, or related to the nursery word for "duck." Dilly was also slang for a stagecoach (1818), from French carrosse de diligence (see diligence).
dilly-dally (v.) Look up dilly-dally at Dictionary.com
1741, probably a reduplication of dally. Related: Dilly-dallying.
dilute (v.) Look up dilute at Dictionary.com
1550s, from Latin dilutus, past participle of diluere "dissolve, wash away, dilute," from dis- "apart" + -luere, comb. form of lavere "to wash" (see lave). Related: Diluted; diluting. As an adjective from c. 1600.
dilution (n.) Look up dilution at Dictionary.com
1640s, noun of action from past participle stem of Latin diluere (see dilute).
diluvial (adj.) Look up diluvial at Dictionary.com
"pertaining to a flood" (or The Flood), 1650s, from Late Latin diluvialis, from Latin diluvium "flood, inundation" (see deluge (n.)). Related: Diluvian.
dim (adj.) Look up dim at Dictionary.com
Old English dimm "dark, gloomy, obscure," from Proto-Germanic *dimbaz (source also of Old Norse dimmr, Old Frisian dim, Old High German timber "dark, black, somber"). Not known outside Germanic. Slang sense of "stupid" is from 1892. Related: Dimly; dimness.
dim (v.) Look up dim at Dictionary.com
c. 1200, perhaps in Old English, from dim (adj.). Related: Dimmed; dimming.
dim sum (n.) Look up dim sum at Dictionary.com
1948, from Cantonese dim sam (Chinese dianxin) "appetizer," said to mean literally "touch the heart."
dime (n.) Look up dime at Dictionary.com
chosen 1786 as name for U.S. 10 cent coin, from dime "a tenth, tithe" (late 14c.), from Old French disme (Modern French dîme) "a tenth part," from Latin decima (pars) "tenth (part)," from decem "ten" (see ten).

The verb meaning "to inform" (on someone) is 1960s, from the then-cost of a pay phone call. A dime a dozen "almost worthless" first recorded 1930. Phrase stop on a dime attested by 1927 (a dime being the physically smallest unit of U.S. currency; turn on a dime is from 1913).
dimension (n.) Look up dimension at Dictionary.com
late 14c., "measurement, size," from Latin dimensionem (nominative dimensio) "a measuring," noun of action from past participle stem of dimetri "to measure out," from dis- (see dis-) + metiri "to measure" (see measure (v.)). Meaning "any component of a situation" is from 1929. Related: Dimensional; dimensions.
diminish (v.) Look up diminish at Dictionary.com
early 15c., from merger of two obsolete verbs, diminue and minish. Diminue is from Old French diminuer "make small," from Latin diminuere "break into small pieces," variant of deminuere "lessen, diminish," from de- "completely" + minuere "make small" (see minus).

Minish is from Old French menuisier, from Latin minuere. Related: Diminished; diminishes; diminishing.
diminuendo Look up diminuendo at Dictionary.com
1775, from Italian diminuendo "lessening, diminishing," present participle of diminuire, from Latin deminuere (see diminish).
diminution (n.) Look up diminution at Dictionary.com
c. 1300, from Anglo-French diminuciun, Old French diminucion, from Latin diminutionem (nominative diminutio), earlier deminutionem, noun of action from past participle stem of deminuere (see diminish).
diminutive (adj.) Look up diminutive at Dictionary.com
in grammar, late 14c. (also as a noun, "derivative word denoting a small or inferior example of what is meant by the word it is derived from"), from Old French diminutif (14c.), from Latin diminutivus, earlier deminutivus, from past participle stem of deminuere (see diminish).
dimity (n.) Look up dimity at Dictionary.com
mid-15c., from Italian dimiti, plural of dimito, a name for a kind of strong cotton cloth, from Medieval Latin dimitum, from Greek dimitos "of double thread," from di- (see di- (1)) + mitos "warp thread, thread" (see mitre).
dimmer (n.) Look up dimmer at Dictionary.com
1822, agent noun from dim (v.). Of mechanisms for reducing the brightness of electric lights, from 1905.
dimorphous (adj.) Look up dimorphous at Dictionary.com
1832, from Greek dimorphos "of two forms," from di- (see di- (1)) + morphe "form, shape" (see Morpheus).
dimple (n.) Look up dimple at Dictionary.com
c. 1400, perhaps existing in Old English as a word meaning "pothole," perhaps ultimately from Proto-Germanic *dumpilaz, which has yielded words in other languages meaning "small pit, little pool" (such as German Tümpel "pool," Middle Low German dümpelen, Dutch dompelen "to plunge"). Related: Dimples.
dimple (v.) Look up dimple at Dictionary.com
1570s (implied in dimpled), from dimple (n.).
dimwit (n.) Look up dimwit at Dictionary.com
also dim-wit, U.S. college slang by 1922, from dim (adj.) + wit (n.). Related: dimwitted.
din (n.) Look up din at Dictionary.com
Old English dyne (n.), dynian (v.), from Proto-Germanic *duniz (source also of Old Norse dynr, Danish don, Middle Low German don "noise"), from PIE root *dwen- "to make noise" (source also of Sanskrit dhuni "roaring, a torrent").
Dinah Look up Dinah at Dictionary.com
fem. proper name, in the Old Testament, Jacob's daughter by Leah, from Hebrew Dinah, literally "judgment," from din "to judge."
dinar (n.) Look up dinar at Dictionary.com
Middle Eastern unit of currency, 1630s, from Arabic dinar, from late Greek denarion, from Latin denarius (see denarius).
Dinaric (adj.) Look up Dinaric at Dictionary.com
from Dinara, ancient name of a mountain in Dalmatia.
dine (v.) Look up dine at Dictionary.com
late 13c., from Old French disner (Modern French dîner) "to dine, eat, have a meal," originally "take the first meal of the day," from stem of Gallo-Roman *desjunare "to break one's fast," from Vulgar Latin *disjejunare, from dis- "undo" (see dis-) + Late Latin jejunare "to fast," from Latin iejunus "fasting, hungry" (see jejune).
diner (n.) Look up diner at Dictionary.com
"one who dines, 1815," agent noun from dine. Meaning "railway car for eating" is 1890, American English; of restaurants built to resemble dining cars (or in some cases actual converted dining cars) from 1935. The Diner's Club credit card system dates from 1952.
dinette (n.) Look up dinette at Dictionary.com
1930, from dine + diminutive (or false French) suffix -ette.
ding (v.) Look up ding at Dictionary.com
1819, "to sound as metal when struck," possibly abstracted from ding-dong, of imitative origin. The meaning "to deal heavy blows" is c. 1300, probably from Old Norse dengja "to hammer," perhaps also imitative. Meaning "dent" is 1960s. Related: Dinged; dinging.
ding dong Look up ding dong at Dictionary.com
imitative of the sound of a bell, c. 1560.
ding-a-ling (n.) Look up ding-a-ling at Dictionary.com
"one who is crazy," 1935, from notion of hearing bells in the head (see ding (v.)).
dingbat (n.) Look up dingbat at Dictionary.com
1838, American English, some kind of alcoholic drink, of unknown origin. One of that class of words (such as dingus, doohickey, gadget, gizmo, thingumabob) which are conjured up to supply names for items whose proper names are unknown or not recollected. Used at various periods for "money," "a professional tramp," "a muffin," "a typographical ornament," "male genitalia," "a Chinese," "an Italian," "a woman who is neither your sister nor your mother," and "a foolish person in authority." Popularized in sense of "foolish person" by U.S. TV show "All in the Family" (1971-79), though this usage dates from 1905.