deport (v.1)
late 15c., "to behave," from Old French deporter "behave, deport (oneself)" (12c.), also with a wide range of meanings in Old French, such as "be patient; take one's (sexual) pleasure with; amuse, entertain; remain, delay, tarry; cheer, console, treat kindly; put aside, cast off, send away," from de- "from, off" (see de-) + porter "to carry," from Latin portare "to carry" (see port (n.1)). Related: Deported; deporting.
deport (v.2)
"banish," 1640s, from French déporter, from Latin deportare "carry off, transport, banish, exile," from de- in its sense of "off, away" (see de-) + portare "to carry" (but associated by folk etymology with portus "harbor"); see port (n.1). Related: Deported; deporting.
deportation (n.)
1590s, from Middle French déportation, from Latin deporationem (nominative deportatio), noun of action from past participle stem of deportare (see deport (v.2)).
deportee (n.)
1895; see deport (v.2) + -ee.
deportment (n.)
c.1600, from Middle French déportement, from déporter "to behave," from Old French deporter (see deport (v.1)).
depose (v.)
c.1300, from Old French deposer (12c.), from de- "down" (see de-) + poser "put, place" (see pose (v.1)). Related: Deposed; deposing.
deposit (v.)
1620s, from Latin depositus, past participle of deponere "lay aside, put down, deposit," also used of births and bets, from de- "away" (see de-) + ponere "to put" (see position). Related: Deposited; depositing.
deposit (n.)
1620s, from Latin depositum, from deponere (see deposit (v.)). Geological sense is from 1781; monetary sense is from 1737.
deposition (n.)
late 14c., "dethronement, putting down from dignity or authority," from Old French deposicion (12c.), from Latin depositionem (nominative depositio), noun of action from past participle stem of deponere (see deposit (v.)).

Meaning "statements made in court under oath" is from early 15c. Meaning "action of depositing" is from 1590s. Properly, deposition belongs to deposit, but deposit and depose have become totally confused and English deposition partakes of senses belonging to both.
depositor (n.)
1560s, agent noun in Latin form from deposit (v.).
depository (n.)
"place where things are deposited," 1750, from Medieval Latin depositorium, from deposit-, past participle stem of Latin deponere (see deposit (v.)) + -orium (see -ory).
depot (n.)
1795, "warehouse," from French dépôt "a deposit, place of deposit," from Old French depost "a deposit or pledge," from Latin depositum "a deposit," noun use of neuter past participle of deponere "lay aside" (see deposit (v.)). Military sense is from 1798; meaning "railway station" is first recorded 1842, American English.
deprave (v.)
late 14c., "corrupt, lead astray, pervert," from Old French depraver (14c.) or directly from Latin depravare "distort, disfigure;" figuratively "to pervert, seduce, corrupt," from de- "completely" (see de-) + pravus "crooked." Related: Depraved; depraving.
depravity (n.)
1640s; see deprave + -ity. Earlier in same sense was pravity.
deprecate (v.)
1620s, "to pray against or for deliverance from," from Latin deprecatus, past participle of deprecari "to pray (something) away" (see deprecation). Meaning "to express disapproval" is from 1640s. Related: Deprecated, deprecating.
deprecation (n.)
c.1500, "prayer to avert evil," from Middle French deprécation, from Latin deprecationem (nominative deprecatio), from past participle stem of deprecari "plead in excuse, avert by prayer," literally "to pray (something) away," from de- "away" (see de-) + precari "pray" (see pray). Sense of "disapproval" is first attested 1610s.
deprecative (adj.)
mid-15c., "praying for deliverance," from Middle French déprécatif (13c.), from Late Latin deprecativus, from past participle stem of Latin deprecari (see deprecation). Related: Deprecatively.
deprecatory (adj.)
1580s, from Late Latin deprecatorius, from deprecat-, past participle stem of deprecari (see deprecation).
depreciate (v.)
mid-15c., from Latin depretiatus, past participle of depretiare "to lower the price of, undervalue," from de- "down" (see de-) + pretium "price" (see price (n.)). Related: Depreciated; depreciating; depreciatory.
depreciation (n.)
1767, "a lowering of value" (originally of currency), noun of action from depreciate. Meaning "loss of value of a durable good by age or wear" is from 1900.
depredate (v.)
1620s, from Latin depredatus, past participle of depraedare "to pillage, ravage" (see depredation).
depredation (n.)
late 15c., from Middle French déprédation, from Late Latin depraedationem (nominative depraedatio) "a plundering," from past participle stem of Latin depraedari "to pillage," from de- "thoroughly" (see de-) + praedari "to plunder," literally "to make prey of," from praeda "prey" (see prey).
depress (v.)
early 14c., "put down by force," from Old French depresser, from Late Latin depressare, frequentative of Latin deprimere "press down," from de- "down" (see de-) + premere "to press" (see press (v.1)). Meaning "push down physically" is from early 15c.; that of "deject, make gloomy" is from 1620s; economic sense of "lower in value" is from 1878. Related: Depressed; depressing.
depressant (n.)
"sedative," 1876 as a noun, 1887 as an adjective; see depress + -ant.
depression (n.)
late 14c. as a term in astronomy, from Old French depression (14c.) or directly from Latin depressionem (nominative depressio), noun of action from past participle stem of deprimere "to press down, depress" (see depress).

Attested from 1650s in the literal sense; meaning "dejection, depression of spirits" is from early 15c. (as a clinical term in psychology, from 1905); meteorological sense is from 1881 (in reference to barometric pressure); meaning "a lowering or reduction in economic activity" was in use by 1826; given a specific application (with capital D-) by 1934 to the one that began worldwide in 1929. For "melancholy, depression" an Old English word was grevoushede.
depressive (adj.)
1610s, from Latin depress-, past participle stem of deprimere (see depress) + -ive. In psychology, from 1905.
deprivation (n.)
mid-15c., "removal from office or position," from Medieval Latin deprivationem (nominative deprivatio), noun of action from past participle stem of deprivare (see deprive).
deprive (v.)
mid-14c., from Old French depriver, from Medieval Latin deprivare, from Latin de- "entirely" (see de-) + privare "release from" (see private). Replaced Old English bedælan. Related: Deprived; depriving.
deprived (adj.)
1550s, "dispossessed," past participle adjective from deprive. As a euphemism for the condition of children who lack a stable home life, by 1945.
deprogram (v.)
"release from cult brainwashing," 1973, from de- + program (v.). Related: Deprogrammed; deprogramming.
dept.
abbreviation of department, attested from 1869.
depth (n.)
late 14c., apparently formed in Middle English on model of length, breadth; from Old English deop "deep" (see deep) + -th (2). Replaced older deopnes "deepness." Though the English word is relatively recent, the formation is in Proto-Germanic, *deupitho-, and corresponds to Old Saxon diupitha, Dutch diepte, Old Norse dypð, Gothic diupiþa.
deputation (n.)
late 14c., noun of action from depute (v.).
depute (v.)
mid-14c., "to appoint, assign," from Middle French deputer, from Late Latin deputare "destine, allot" (see deputy). Related: Deputed; deputing.
deputize (v.)
1730s; see deputy + -ize. Related: Deputized; deputizing.
deputy (n.)
c.1400, "one given the full power of an officer without holding the office," from Anglo-French deputé, noun use of past participle of Middle French députer "appoint, assign" (14c.), from Late Latin deputare "to destine, allot," in classical Latin "to esteem, consider, consider as," literally "to cut off, prune," from de- "away" (see de-) + putare "to think, count, consider," literally "to cut, prune" (see pave).
deracinate (n.)
1590s, "to pluck up by the roots," from French déraciner, from Old French desraciner "uproot, dig out, pull up by the roots," from des- (see dis-) + racine "root," from Late Latin radicina, diminutive of Latin radix (see radish). Related: Deracinated.
derail (v.)
1850, in both transitive and intransitive senses, from French dérailler "to go off the rails," from de- (see de-) + railler (see rail (n.1)). In general use first in U.S. Related: Derailed; derailing.
derailleur (n.)
type of bicycle gear mechanism, 1930, from French dérailleur (1927), from dérailler "to go off the rails" (see derail).
derailment (n.)
1850, from French déraillement, from dérailler "to go off the rails" (see derail).
derange (v.)
1776, "throw into confusion," from French déranger, from Old French desrengier "disarrange, throw into disorder," from des- "do the opposite of" (see dis-) + Old French rengier (Modern French ranger) "to put into line," from reng "line, row," from a Germanic source (see rank (n.)). Mental sense first recorded c.1790.
deranged (adj.)
c.1790, "insane;" of things, "out of order," from 1796; past participle adjective from derange (v.).
derangement (n.)
1737, "disturbance of regular order," from French dérangement (17c.), from déranger (see derange). Of mental order, from 1800.
derby (n.)
type of hat," manufactured in U.S. 1850, name appears 1870, perhaps from annual Derby horse race in England, where this type of hat was worn. Race was begun 1780 by the 12th Earl of Derby; the name was used for any major horse race after 1875. Derby the English shire is Old English Deorby "deer village," from deor "deer" + by "habitation, homestead," from a Scandinavian source (see bylaw).
derecho (n.)
from American Spanish derecho, from Old Spanish diestro, from Latin directus (see direct (v.)).
deregulate (v.)
1963, back-formation from deregulation. Related: Deregulated; deregulating.
derelict (adj.)
1640s, from Latin derelictus "solitary, deserted," past participle of dereliquere "to abandon, forsake, desert," from de- "entirely" + relinquere "leave behind" (see relinquish). Originally especially of vessels abandoned at sea or stranded on shore. As a noun, from 1660s.
dereliction (n.)
1590s, "abandonment" (formerly with a wider range than in modern use, such as of the sea withdrawing from the land), from Latin derelictionem (nominative derelictio), noun of action from past participle stem of derelinquere (see derelict). Meaning "failure in duty" is from c.1830.
deride (v.)
1520s, from Middle French derider, from Latin deridere "to ridicule, laugh to scorn" (see derision). Related: Derided; deriding.
derision (n.)
c.1400, from Old French derision "derision, mockery" (13c.), from Latin derisionem (nominative derisio), noun of action from past participle stem of deridere "ridicule," from de- "down" (see de-) + ridere "to laugh."