Online Etymology Dictionary

document (v.): 1640s, "to teach;" see document (n.). Meaning "to support by documentary evidence" is from 1711. Related: Documented; documenting.
documentary (adj.): c.1810, "pertaining to documents," from document + -ary. Meaning "factual, meant to provide a record of something" is from 1926, from French film documentarie (1924). The noun (short for documentary film) is attested from 1935. Docudrama is a 1961 coinage.
documentation (n.): 1754, "admonition," from Medieval Latin documentationem (nominative documentio) "admonition" (see document). Meaning "furnishing with documents or papers" is from 1884, probably from document. Meaning "collection of informational papers" is from 1927.
dodder (v.): 1610s, perhaps from Middle English daderen "to quake, tremble" (late 15c.), apparently frequentative of dialectal dade, on a form similar to totter, patter. Related: Doddered; doddering.
dodecahedron (n.): 1560s, from Greek dodeka "twelve" (short for duodeka, from duo "two" + deka "ten;" cf. dozen) + hedra "seat, base, chair, face of a geometric solid," from PIE root *sed- "to sit" (see sedentary).
dodge (n.): "person's way of making a living," 1842, slang, from dodge (v.).
dodge (v.): "to move to and fro" (especially in an effort to avoid something), 1560s, origin and sense evolution obscure, perhaps akin to Scottish dodd "to jog." Common from early 18c. in figurative sense of "to swindle, to play shifting tricks." Related: Dodged; dodging.
dodger (n.): 1560s, "one who dodges," in the literal or figurative (especially underworld) senses of dodge. The U.S. word meaning "corn cake" is recorded from 1831, perhaps a different word (cf. Northern English dialectal dodge "lump, large piece," 1560s).
Dodgers: U.S. baseball club, originally based in Brooklyn, N.Y., so called from 1900, from trolley dodgers, Manhattanites' nickname for Brooklyn residents, in reference to the streetcar lines that criss-crossed the borough.
dodgy (adj.): 1861, from dodge + -y (2). Related: Dodginess.
dodo (n.): 1620s, from Portuguese doudo "fool, simpleton," an insult applied by Portuguese sailors to the awkward bird (Didus ineptus) they found on Mauritius island. The last record of a living one is from 1681. Applied in English to stupid persons since 1886.
doe (n.): Old English da "a female deer," of unknown origin, perhaps a Celtic loan-word (cf. Cornish da "fallow deer," Old Irish dam "ox," Welsh dafad "sheep").
doer (n.): c.1300, agent noun from do.
does: third person singular present of do (v.), originally a Northumbrian variant in Old English that displaced doth, doeth 16c.-17c.
doesn't: 1690s, contraction of does not.
doff (v.): mid-14c., contraction of do off, preserving the original sense of do as "put." At the time of Johnson's Dictionary [1755] the word was "obsolete, and rarely used except by rustics," but it was saved from extinction (along with don) by Sir Walter Scott. Related: Doffed; doffing.
dog (n.): Old English docga, a late, rare word used of a powerful breed of canine. It forced out Old English hund (the general Germanic and Indo-European word; see canine) by 16c. and subsequently was picked up in many continental languages (e.g. French dogue (16c.), Danish dogge), but the origin remains one of the great mysteries of English etymology.

Many expressions -- a dog's life (c.1600), go to the dogs (1610s), etc. -- reflect earlier hard use of the animals as hunting accessories, not pampered pets. In ancient times, "the dog" was the worst throw in dice (attested in Greek, Latin, and Sanskrit, where the word for "the lucky player" was literally "the dog-killer"), which plausibly explains the Greek word for "danger," kindynas, which appears to be "play the dog."

Slang meaning "ugly woman" is from 1930s; that of "sexually aggressive man" is from 1950s. Adjectival phrase dog-eat-dog attested by 1850s. Dog tag is from 1918. To dog-ear a book is from 1650s; dog-eared in extended sense of "worn, unkempt" is from 1894.
Notwithstanding, as a dog hath a day, so may I perchance have time to declare it in deeds. [Princess Elizabeth, 1550]

It is ill wakyng of a sleapyng dogge. [Heywood, 1562]
Phrase put on the dog "get dressed up" (1934) may look back to the stiff stand-up shirt collars that in the 1890s were the height of male fashion (and were known as dog-collars at least from 1883), with reference to collars worn by dogs. The common Spanish word for "dog," perro, also is a mystery word of unknown origin, perhaps from Iberian. A group of Slavic "dog" words (Old Church Slavonic pisu, Polish pies, Serbo-Croatian pas) likewise are of unknown origin.
dog (v.): "to track like a dog," 1510s, see dog (n.). Related: Dogged; dogging.
dog days (n.): 1530s, from Latin dies caniculares, from Greek; so called because they occur around the time of the heliacal rising of Sirius, the Dog Star (kyon seirios). Noted as the hottest and most unwholesome time of the year; usually July 3 to Aug. 11, but variously calculated, depending on latitude and on whether the greater Dog-star (Sirius) or the lesser one (Procyon) is reckoned.

The heliacal rising of Sirius has shifted down the calendar with the precession of the equinoxes; in ancient Egypt c.3000 B.C.E. it coincided with the summer solstice, which also was the new year and the beginning of the inundation of the Nile. The "dog" association apparently began here (the star's hieroglyph was a dog), but the reasons for it are obscure.
dog leg (n.): "something bent like a dog's hind leg," 1703. Originally of a type of staircase.
doge (n.): "chief magistrate of Venice or Genoa," 1540s, from Venetian dialect doge, from Latin ducem, accusative of dux "leader" (see duke (n.)).
dogfight (n.): "aerial combat," World War I air forces slang, from earlier meaning "riotous brawl" (1880s); from dog (n.) + fight (n.). The literal sense of "a fight among or between dogs" is from 1650s.
dogfish (n.): a name for various types of small shark, late 15c., dokefyche, from dog (n.) + fish (n.). Said to be so called because they hunt in packs. This was the image of sharks in classical antiquity as well.
But in the Mediterranean, among the Greeks and Romans of antiquity, closer contact with sharks had left an impression of vicious dogs of the sea. Thus, Pliny's canis marinus. The metaphor of the dog spread to the North to dominate the European image of the shark, from the Italian pescecane and French chien de mer to the German Meerhund and Hundfisch and English sea dog and dogfish. [Tom Jones, "The Xoc, the Sharke and the Sea Dogs," in "Fifth Palenque Round Table, 1983," edited by Virginia M. Field, 1985.]
dogged (adj.): "having the qualities of a dog" (mostly in a negative sense), c.1300, from dog (n.). Meaning "persistent" is from 1779. Hence doggedly (late 14c.), "cruelly, maliciously;" later "with a dog's persistence" (1773). Related: Doggedness.
dogger (n.): "two-masted fishing boat," used in North Sea fishery, mid-14c., of unknown origin. It likely is the source of the name Dogger Bank (1660s) for the great banks of shoals in the North Sea.
doggerel: late 14c. (adj.); 1630s (n.), probably from dog + pejorative suffix -rel and applied to bad poetry perhaps with a suggestion of puppyish clumsiness, or being fit only for dogs. Attested as a surname from mid-13c., but the sense is not evident.
doggone (adj.): 1851, American English, a "fantastic perversion of god-damned" [Weekley]. But Mencken favors the theory that it is "a blend form of dog on it; in fact it is still often used with it following. It is thus a brother to the old English phrase, 'a pox upon it,' but is considerably more decorous."
doggy (n.): also doggie, 1825, from dog (n.) + -y (3). Doggy-bag attested from 1965. As an adj. doggy is attested from late 14c., from -y (2). The word has been used in various formations since at least late 19c. to describe the sex act when one partner is on all fours.
doghouse (n.): 1610s, from dog (n.) + house (n.). Originally a kennel; the backyard type, for a single animal, is late 19c. Figurative sense of "disgrace" is from 1932.
dogie (n.): "motherless calf in a herd," 1887, cowboy slang, of uncertain origin.
dogma (n.): c.1600 (in plural dogmata), from Latin dogma "philosophical tenet," from Greek dogma (genitive dogmatos) "opinion, tenet," literally "that which one thinks is true," from dokein "to seem good, think" (see decent). Treated in 17c.-18c. as a Greek word in English.
dogmatic (adj.): 1670s, from Late Latin dogmaticus, from Greek dogmatikos "pertaining to doctrines," from dogma (see dogma). Related: Dogmatical (c.1600).
dogmatism (n.): c.1600, but not in common use until 19c., from French dogmatisme (16c.), from Medieval Latin dogmatismus, from Latin dogma (see dogma).
dogs (n.): "feet," 1913, from rhyming slang dog's meat.
dogwood (n.): shrubs and small trees of the genus Cornus, 1610s, earlier dog-tree (1540s); the first element sometimes said to have been perhaps dag -- cf. dagger, dag (v.) "to pierce or stab" (1630s, perhaps 15c.) -- the trees have hard, white wood that was used in making skewers; another name for it was skewer-wood. But another guess is that the tree was given the name in reference to its fruit, which was called dogberry from 1550s, and dog had implications of "cheap, inferior" (i.e. "fit for a dog").
doily (n.): 1714, short for doily-napkin (1711), from doily "thin, woolen fabric;" supposedly from Doiley, surname of a 17c.-early 18c. dry-goods dealer on London's Strand. Doily earlier meant "genteel, affordable woolens" (1670s), evidently from the same source. The surname is d'Ouilly, from one of several places called Ouilly in Normandy.
doing (n.): early 13c., verbal noun from do (v.). From c.1600-1800 it also was a euphemism for "copulation."
dojo (n.): "hall in which judo is practiced," 1942, from Japanese.
dol (n.): unit of intensity of pain, 1947, from Latin dolor "pain."
Dolby: sound reproduction system, 1966, named for its inventor, U.S. engineer Ray M. Dolby (b.1933).
dolce far niente: 1814, from Italian, literally "sweet doing nothing." The Latin roots are dulcis "sweet" (see dulcet), facere "to make, do," and nec entem, literally "not a being."
This phrase, frequent enough in English literature, does not seem to occur in any Italian author of note. Howells says that he found it current among Neapolitan lazzaroni, but it is not included in any collection of Italian proverbial sayings. [Walsh]
dolce vita (n.): "life of pleasure," 1960, Italian, from title of Fellini's film.
doldrums (n.): 1811, from dulled, past participle of dullen, from Old English dol "foolish, dull," ending perhaps patterned on tantrum.
dole (n.): Old English dal "state of being divided; sharing, giving out," shortened from gedal "portion," related to dæl "deal," from Proto-Germanic *dailiz (cf. Old Frisian and Old Saxon del, Middle Dutch deil, Dutch deel, Old High German teil, German Teil). On the dole is 1920s.
dole (v.): "hand out charity," mid-15c., from dole (n.). Doled; doling.
doleful (adj.): late 13c., with -ful, from Middle English dole "grief" (early 13c.), from Old French doel (Modern French deuil), from Late Latin dolus "grief," from Latin dolere "suffer, grieve." Related: Dolefully.
doll (n.): 1550s, endearing name for a female pet or a mistress; originally a familiar form of fem. proper name Dorothy (q.v.). The -l- for -r- substitution in nicknames is common in English: cf. Hal for Harold, Moll for Mary, Sally for Sarah, etc. Attested from 1640s as colloquial for "slattern;" sense of "child's toy baby" is c.1700. Transferred back to living beings 1778 in sense of "pretty, silly woman."
doll (v.): 1867, "to pet, indulge," from doll (n.). Usually with up. Meaning "to dress up" is from 1906, American English. Related: Dolled; dolling.
dollar (n.): 1550s, from Low German daler, from German taler (1530s, later thaler), abbreviation of Joachimstaler, literally "(gulden) of Joachimstal," coin minted 1519 from silver from mine opened 1516 near Joachimstal, town in Erzgebirge Mountains in northwest Bohemia. German Tal is cognate with English dale.

The thaler was a large silver coin of varying value in the German states (and a unit of the German monetary union of 1857-73 equal to three marks); it also served as a currency unit in Denmark and Sweden. English colonists in America used the word in reference to Spanish pieces of eight. Continental Congress July 6, 1785, adopted dollar when it set up U.S. currency, on suggestion of Gouverneur Morris and Thomas Jefferson, because the term was widely known but not British. But none were circulated until 1794.
When William M. Evarts was Secretary of State he accompanied Lord Coleridge on an excursion to Mount Vernon. Coleridge remarked that he had heard it said that Washington, standing on the lawn, could throw a dollar clear across the Potomac. Mr. Evarts explained that a dollar would go further in those days than now. [Walsh]
The dollar sign ($) is said to derive from the image of the Pillars of Hercules, stamped with a scroll, on the Spanish piece of eight. Phrase dollars to doughnuts attested from 1890; dollar diplomacy is from 1910.
dollhouse (n.): 1855, from doll (n.) + house (n.). Doll's house first recorded 1783.