Online Etymology Dictionary

derivation (n.): early 15c., from Middle French dérivation (14c.), from Latin derivationem (nominative derivatio) "a leading off, turning away," noun of action from past participle stem of derivare (see derive). Grammatical sense is older; general meaning "origination, descent" is from c. 1600.
derivative: early 15c. (adj.); mid-15c. (n.), from Middle French dérivatif (15c.), from Late Latin derivat-, past participle stem of Latin derivare (see derive). Mathematical sense is from 1670s.
derive (v.): late 14c., from Old French deriver "to flow, pour out; derive, originate," from Latin derivare "to lead or draw off (a stream of water) from its source" (in Late Latin also "to derive"), from phrase de rivo (de "from" + rivus "stream;" see rivulet). Etymological sense is 1550s. Related: Derived; deriving.
derm (n.): 1835, from Greek derma "skin, hide, leather" (see derma).
derma (n.): "skin beneath the epidermis," 1706, from Modern Latin derma, from Greek derma (genitive dermatos) "skin," from PIE root *der- (2) "to split, peel, flay" (see tear (v.1)).
dermabrasion (n.): 1954; see derma + abrasion.
dermal (adj.): 1803; see derm + -al (1). A native formation, the Greek adjective would be dermatikos, yielding *dermatic.
dermatitis (n.): 1851; see dermato- + -itis "inflammation."
dermato-: before vowels, dermat-, word-forming element meaning "of or pertaining to skin," from Greek dermato- (shortened form dermo-), from derma "skin" (see derma).
dermatologist (n.): 1833; see dermatology + -ist.
dermatology (n.): 1819, from dermato- + -logy. Related: Dermatological.
dermis (n.): 1830, perhaps from Latinized form of Greek derma "skin" (see derma); or perhaps a back-formation from epidermis.
dern (adj.): "secret, hidden" (obsolete), from Old English derne "concealed, secret, dark," from West Germanic *darnjaz (source also of Old Saxon derni, Old Frisian dern "concealed, dark," Old High German tarni "secret, concealed, veiled").

As a verb, "to conceal," from Old English diernan "to hide." Compare Old High German tarnjan "to conceal, hide;" German Tarnkappe, Tarnhelm "magical cap or helmet which turns the wearer invisible or allows him to assume any form." Related to dark (adj.). French ternir "to tarnish, to dull" apparently is a Germanic loan-word.
derogate (v.): early 15c., "impair (authority); disparage (reputation)," from Latin derogatus, past participle of derogare "diminish" (see derogatory).
derogation (n.): mid-15c., from Old French dérogacion (14c.), from Latin derogationem (nominative derogatio), noun of action from past participle stem of derogare (see derogatory).
derogative (adj.): late 15c., from Middle French derogatif, from Latin *derogativus, from past participle stem of derogare (see derogatory).
derogatory (adj.): c. 1500, from Late Latin derogatorius, from Latin derogatus, past participle of derogare "to take away, detract from, diminish," also "repeal partly, restrict, modify," from de- "away" (see de-) + rogare "ask, question, propose" (see rogation).
derrick (n.): c. 1600, originally "hangman," then "a gallows," then "hoist, crane" (1727), from surname of a hangman at Tyburn gallows, London, c. 1606-1608, often referred to in contemporary theater. The name represents a late borrowing from the Low Countries (compare Dutch Diederik) of Old High German Theodric (see Dietrich).
derriere (n.): 1774, from French derrière "back part, rear," originally an adverb, "behind, behind the back" (12c.), from Late Latin deretro, from Latin de "from" (see de-) + retro "back" (see retro-).
derring-do (n.): originally (late 14c.) dorrying don, literally "daring to do," from durring "daring," present participle of Middle English durren "to dare" (see dare (v.)) + don, infinitive of do (v.). Misspelled derrynge do 1500s and mistaken for a noun by Spenser, who took it to mean "manhood and chevalrie;" picked up from him and passed on to Romantic poets as a pseudo-archaism by Sir Walter Scott.
derringer (n.): 1850, for Henry Deringer (1786-1868), U.S. gunsmith who invented it in the 1840s; prevailing misspelled form is how his name appeared on the many counterfeits and imitations. "A small pistol with a large bore, very effective at short range" [OED].
dervish (n.): 1580s, from Turkish dervish, from Persian darvesh, darvish "beggar, poor," hence "religious mendicant;" equivalent of Arabic faqir (see fakir). The "whirling dervishes" are just one order among many. Originally dervis; modern spelling is from mid-19c.
Des Moines: city in Iowa, U.S., named for French Rivière des Moines, the river that flows past it, which traditionally is derived from French des moines "of the monks," in reference to missionaries, but this probably is a fur trappers' folk-etymologizing of a name of the native people who lived there.

The place appears in a 1673 text as Moinguena, and historians believe this represents Miami-Illinois mooyiinkweena, literally "shitface," from mooy "excrement" + iinkwee "face;" a name given by the Peoria Indians (whose name has itself become a sort of insult) to their western neighbors. It is not unusual for Indian peoples to have hostile or derogatory names for others, but this seems an extreme case.
des-: the usual form of Latin dis- in Old Italian, Spanish, Portuguese, Provençal, French.
desalination (n.): 1943, from de- + salination. As a verb, desalt is recorded from 1909.
descant (n.): late 14c., from Old North French descant (Old French deschant), from Medieval Latin discantus "refrain, part-song," from Latin dis- "asunder, apart" (see dis-) + cantus "song" (see chant). Spelling was partly Latinized 16c. Originally "counterpoint."
descant (v.): mid-15c.; see descant (n.). Sense of "to comment at length" is first attested 1640s.
descend (v.): c. 1300, from Old French descendre (10c.) "descend, dismount; fall into; originate in," from Latin descendere "come down, descend, sink," from de- "down" (see de-) + scandere "to climb," from PIE root *skand- "jump" (see scan (v.)). Sense of "originate" is late 14c. in English. Related: Descended; descending.
descendant: mid-15c. (adj.), c. 1600 (n.), from French descendant (13c.), present participle of descendre (see descend). Despite a tendency to use descendent for the adjective and descendant for the noun, descendant seems to be prevailing in all uses and appears 5 times more often than its rival in books printed since 1900. Compare dependant.
descendent: see descendant.
descender (n.): in typography, "part of a letter that extends below the body," 1802, agent noun from descend.
descension (n.): early 15c., from Old French descension, from Latin descensionem (nominative descensio) "a going down, descending," noun of action from descensus, past participle of descendere (see descend).
descent (n.): c. 1300, from Old French descente "descent, descendance, lineage," formed from descendre (see descend) on analogy of French nouns such as attente from attendre "to expect," vente "sale" from vendre "to sell," pente "slope" from pendre "to hang" (the etymological English word from Latin would be *descence).

Figurative use is from late 14c. Meaning "action of descending," also "a downward slope" is from 1590s. Meaning "act of descending from an ancestor" is from mid-14c. Evolutionary sense is from 1859 in Darwin, though there are uses which suggest essentially the same thing going back to 1630s.
deschooling (n.): 1970, coined by Austrian-born U.S. anarchist philosopher Ivan Illich (1926-2002) for "the transfer of education to non-institutional systems;" see de- + schooling.
describe (v.): early 13c., descriven, from Old French descrivre, descrire (13c.), from Latin describere "to write down, copy; sketch, represent" (see description). Reconstructed with Latin spelling 16c. Related: Describable; described, describes, describing.
description (n.): late 14c., from Old French description (12c.) and directly from Latin descriptionem (nominative descriptio) "representation, description, copy," noun of action from past participle stem of describere "write down, transcribe, copy, sketch," from de- "down" (see de-) + scribere "write" (see script (n.)).
descriptive (adj.): 1751, from Late Latin descriptivus, from descript-, past participle stem of describere (see description). Related: Descriptively; descriptiveness.
descry (v.1): "to see, discern," c. 1300, probably from Old French descrier "publish" (Modern French décrier), from Latin describere (see describe).
descry (v.2): "to proclaim," mid-14c., from Old French descrier, from des- (see dis-) + crier, from Latin quiritare (see cry (v.)).
desecrate (v.): 1670s, formed from de- "do the opposite of" (see de-) + stem of consecrate. Old French had dessacrer "to profane," and there is a similar formation in Italian; but Latin desecrare meant "to make holy," with de- in this case having a completive sense. Related: Desecrated; desecrating.
desecration (n.): 1717, noun of action from desecrate (v.).
desegregate (v.): 1948, back-formation from desegregation. Related: Desegregated; desegregating.
desegregation (n.): 1935, American English, from de- "do the opposite of" + segregation in the racial sense.
desensitize (v.): 1904; see de- "do the opposite of" + sensitize. Originally of photography development; psychological sense is first recorded 1935. Related: Desensitized; desensitizing.
desert (v.): "to leave one's duty," late 14c., from Old French deserter (12c.) "leave," literally "undo or sever connection," from Late Latin desertare, frequentative of Latin deserere "to abandon, to leave, forsake, give up, leave in the lurch," from de- "undo" (see de-) + serere "join together, put in a row" (see series). Military sense is first recorded 1640s. Related: Deserted; deserting.
desert (n.1): "wasteland," early 13c., from Old French desert (12c.) "desert, wilderness, wasteland; destruction, ruin," from Late Latin desertum (source of Italian diserto, Old Provençal dezert, Spanish desierto), literally "thing abandoned" (used in Vulgate to translate "wilderness"), noun use of neuter past participle of Latin deserere "forsake" (see desert (v.)).

Sense of "waterless, treeless region" was in Middle English and gradually became the main meaning. Commonly spelled desart in 18c., which is not etymological but at least avoids confusion with the other two senses of the word. Classical Latin indicated this idea with deserta, plural of desertus.
Every important worker will report what life there is in him. It makes no odds into what seeming deserts the poet is born. Though all his neighbors pronounce it a Sahara, it will be a paradise to him; for the desert which we see is the result of the barrenness of our experience. [Thoreau, Journal, May 6, 1854]
desert (n.2): "suitable reward or punishment" (now usually plural and with just), c. 1300, from Old French deserte, noun use of past participle of deservir "be worthy to have," ultimately from Latin deservire "serve well" (see deserve).
deserter (n.): 1630s, agent noun from desert (v.).
desertification (n.): 1973, from desert (n.1) + -fication. In French, désertisation is attested from 1968.
desertion (n.): 1590s, from Middle French désertion (early 15c.), from Late Latin desertionem (nominative desertio) "a forsaking, abandoning," noun of action from past participle stem of Latin deserere (see desert (v.)).