Online Etymology Dictionary

entrenchment (n.): also intrenchment, 1580s, from entrench + -ment.
entrepot (n.): "warehouse," 1758, from French entrepôt (16c.), from Latin interpositum "that which is placed between," neuter past participle of interponere "to place between" (see interposition).
entrepreneur (n.): 1828, "manager or promoter of a theatrical production," reborrowing of French entrepreneur "one who undertakes or manages," agent noun from Old French entreprendre "undertake" (see enterprise). The word first crossed the Channel late 15c. (Middle English entreprenour) but did not stay. Meaning "business manager" is from 1852. Related: Entrepreneurship.
entrepreneurial (adj.): 1915, from entrepreneur + -ial.
entropy (n.): 1868, from German Entropie "measure of the disorder of a system," coined 1865 (on analogy of Energie) by German physicist Rudolph Clausius (1822-1888), in his work on the laws of thermodynamics, from Greek entropia "a turning toward," from en "in" (see en- (2)) + trope "a turning, a transformation" (see trope). The notion is supposed to be "transformation contents." Related: Entropic.
It was not until 1865 that Clausius invented the word entropy as a suitable name for what he had been calling "the transformational content of the body." The new word made it possible to state the second law in the brief but portentous form: "The entropy of the universe tends toward a maximum," but Clausius did not view entropy as the basic concept for understanding that law. He preferred to express the physical meaning of the second law in terms of the concept of disgregation, another word that he coined, a concept that never became part of the accepted structure of thermodynamics. [Martin J. Klein, "The Scientific Style of Josiah Willard Gibbs," in "A Century of Nathematics in America," 1989]
entrust (v.): also intrust, c. 1600, from en- (1) "make, put in" + trust (n.). Related: Entrusted; entrusting.
entry (n.): c. 1300, "act or fact of physically entering; place of entrance, means of entering a building; opportunity or right of entering; initiation or beginning of an action;" from Old French entree "entry, entrance" (12c.), noun use of fem. past participle of entrer "to enter" (see enter). Meaning "that which is entered or set down (in a book, list, etc.)" is from c. 1500.
entryway (n.): 1746, from entry + way.
entwine (v.): also intwine, 1590s, from en- (1) "make, put in" + twine (n.). Related: Entwined; entwining.
enucleation (n.): 1640s, noun of action from verb enucleate (1540s), from Latin enucleatus "pure, clean," past participle of enucleare "to lay open, explain in detail," literally "to remove the kernel from" (see ex- + nucleus). Mostly figurative in Latin (the notion is of getting at the "core" of some matter), and usually figurative in English until mid-19c. advances in science and medicine gave it a new literal sense.
enumerable (adj.): 1846; see enumerate + -able. Often an error for innumerable.
enumerate (v.): 1640s, from or modeled on Latin enumeratus, past participle of enumerare (see enumeration). Middle English had annumerate (early 15c.). Related: Enumerated; enumerating.
enumeration (n.): 1550s, "action of enumerating," from Middle French énumération, from Latin enumerationem (nominative enumeratio) "a counting up," noun of action from past participle stem of enumerare "to reckon up, count over, enumerate," from assimilated form of ex- "from" (see ex-) + numerare "to count, number," from numerus "number" (see number (n.)). Meaning "a list, catalogue" is from 1724.
enunciate (v.): 1620s, "declare, express," from Latin enunciatus, properly enuntiatus, past participle of enuntiare "speak out, say, express, assert; divulge, disclose, reveal, betray," from assimilated form of ex- "out" (see ex-) + nuntiare "to announce," from nuntius "messenger" (see nuncio). Or perhaps a back-formation from enunciation. Meaning "to articulate, pronounce" is from 1759. Related: Enunciated; enunciating.
enunciation (n.): 1550s, "a declaration," from Latin enuntiationem (nominative enuntiatio) "enunciation, declaration," noun of action from past participle stem of enuntiare "to speak out, say, express" (see enunciate). Meaning "articulation of words" is from 1750.
enunciative (adj.): "declarative, declaring something as true," 1530s, from Latin enunciatus, properly enuntiativus, from past participle stem of enuntiare "to speak out, say, express" (see enunciate).
enuresis (n.): minor urinary incontinence, 1800, medical Latin, from Greek enourein "to urinate in," from en "in" (see en- (2)) + ourein "to urinate," from ouron (see urine).
envelop (v.): late 14c., envolupen, "be involved" (in sin, crime, etc.), from Old French envoleper "envelop, cover; fold up, wrap up" (10c., Modern French envelopper), from en- "in" (see en- (1)) + voloper "wrap up," which is of uncertain origin, perhaps Celtic (see Gamillscheg, Diez) or Germanic ("Century Dictionary"). Literal sense is from 1580s. Related: Enveloped; enveloping.
envelope (n.): "a wrapper, an enclosing cover," specifically a prepared wrapper for a letter or other paper, 1705, from French enveloppe (13c.), a back-formation from envelopper "to envelop" (see envelop).
envelopment (n.): 1751, from envelop (v.) + -ment.
envenom (v.): c. 1300, envenymen, from Old French envenimer (12c.) "to poison, taint;" from en- (see en- (1)) + venim (see venom). Figurative use is from late 14c. Related: Envenomed; envenoming.
enviable (adj.): c. 1600, from envy + -able or from French enviable. Related: Enviably.
envious (adj.): c. 1300, from Anglo-French envious, Old French envieus (13c.), earlier envidius "envious, jealous" (12c., Modern French envieux), from Latin invidiosus "full of envy" (source of Spanish envidioso, Italian invidioso, Portuguese invejoso), from invidia (see envy). Related: Enviously; enviousness.
environ (v.): late 14c. (implied in environing), "to surround, encircle, encompass," from Old French environer "to surround, enclose, encircle," from environ "round about," from en- "in" (see en- (1)) + viron "a circle, circuit," also used as an adverb, from virer "to turn" (see veer). Related: Environed.
environment (n.): c. 1600, "state of being environed" (see environ (v.) + -ment); sense of "the aggregate of the conditions in which a person or thing lives" first recorded 1827 (used by Carlyle to render German Umgebung); specialized ecology sense first recorded 1956.
environmental (adj.): 1887, "environing, surrounding," from environment + -al (1). Ecological sense by 1967. Related: Environmentally (1884).
environmentalism (n.): 1923, as a psychological theory (in the nature vs. nurture debate), from environmental + -ism. The ecological sense is from 1972. Related: Environmentalist (n.), 1916 in the psychological sense, 1970 in the ecological sense.
environs (n.): "outskirts," 1660s, from French environs, plural of Old French environ "compass, circuit," from environ (adv.) "around, round about" (see environ).
envisage (v.): 1778, "look in the face of," from French envisager "look in the face of," from en- "in" (see en- (1)) + visage "face" (see visage). Hence "to apprehend mentally, contemplate" (1837). Related: Envisaged; envisaging; envisagement.
envision (v.): 1914, from en- (1) "make, put in" + vision (n.). Related: Envisioned; envisioning. Earlier (1827) is envision'd in sense "endowed with vision."
envoy (n.): "messenger," 1660s, from French envoyé "messenger; a message; a sending; the postscript of a poem," literally "one sent" (12c.), noun use of past participle of envoyer "send," from Vulgar Latin *inviare "send on one's way," from Latin in "on" (see in- (2)) + via "road" (see via (adv.)). The same French word was borrowed in Middle English as envoi in the sense "stanza of a poem 'sending it off' to find readers" (late 14c.).
envy (n.): late 13c., from Old French envie "envy, jealousy, rivalry" (10c.), from Latin invidia "envy, jealousy" (source also of Spanish envidia, Portuguese inveja), from invidus "envious, having hatred or ill-will," from invidere "to envy, hate," earlier "look at (with malice), cast an evil eye upon," from in- "upon" (see in- (2)) + videre "to see" (see vision).
Jealousy is the malign feeling which is often had toward a rival, or possible rival, for the possession of that which we greatly desire, as in love or ambition. Envy is a similar feeling toward one, whether rival or not, who already possesses that which we greatly desire. Jealousy is enmity prompted by fear; envy is enmity prompted by covetousness. [Century Dictionary]
Similar formations in Avestan nipashnaka "envious," also "look at;" Old Church Slavonic zavideti "to envy," from videti "to see;" Lithuanian pavydeti "to envy," related to veizdeti "to see, to look at."
envy (v.): late 14c., from Old French envier "envy, be envious of," from envie (see envy (n.)). Related: Envied; envying.
enwind (v.): also inwind, 1590s (implied in inwinding), from en- (1) + wind (v.1). Related: Enwound; enwinding.
enwrap (v.): also inwrap, late 14c., from en- (1) "make, put in" + wrap (v.). Related: Enwrapped; enwrapping.
enzyme (n.): 1881, as a biochemical term, from German Enzym, coined 1878 by German physiologist Wilhelm Kühne (1837-1900), from Modern Greek enzymos "leavened," from en "in" (see en- (2)) + zyme "leaven" (see zymurgy). Related: Enzymotic.
eo-: word-forming element, used from mid-19c. (first in Eocene) in compound words formed by earth-scientists, and meaning "characterized by the earliest appearance of," from Greek eos "dawn, morning, daybreak," also the name of the goddess of the morning, from PIE *aus- (1) "to shine," especially of the dawn (see aurora). Piltdown Man, before exposed as a fraud, was known as Eoanthropus.
Eocene (adj.): in reference to the second epoch of the Tertiary Period, 1831, from eo- "earliest" + Latinized form of Greek kainos "new" (see recent). Coined in English (along with Miocene and Pliocene) by the Rev. William Whewell (1794-1866), English polymath, and meant as "the dawn of the recent." As a noun from 1851.
Eohippus (n.): oldest known genus of the horse family, about the size of a fox and first known from fossil remains found in New Mexico, 1879, Modern Latin, from eo- "earliest" + Greek hippos "horse" (see equine).
eolian (adj.): see Aeolian.
eolithic (adj.): "pertaining to the early Stone Age," 1890, from French éolithique (1883), from eo- "earliest" (see eo-) + French lithique, as in néolithique (see neolithic). Related: eolith (1890).
eon (n.): 1640s, from Late Latin aeon, from Greek aion "age, vital force; a period of existence, a lifetime, a generation; a long space of time," in plural, "eternity," from PIE root *aiw- "vital force, life, long life, eternity" (source also of Sanskrit ayu "life," Avestan ayu "age," Latin aevum "space of time, eternity," Gothic aiws "age, eternity," Old Norse ævi "lifetime," German ewig "everlasting," Old English a "ever, always"). Related: Eonian; eonic.
EPA: initialism (acronym) for Environmental Protection Agency, U.S. federal agency proposed by President Richard Nixon and created in December 1970.
epact (n.): 1550s, "a number attached to a year to show the number of days into the calendar moon on which the solar year begins;" 1580s, "number of days by which the solar year exceeds a lunar one of 12 moons;" from French épacte (12c.), from Late Latin epacta "an intercalary day," from Greek epakte (plural epaktai, in epaktai hemerai "intercalary days"), from fem. of epaktos "brought in, imported, alien," verbal adjective of epagein "to add, bring forward," also "intercalate," from epi "on" (see epi-) + agein "to bring, to lead" (see act (v.)). Related: Epactal.
epaulet (n.): also epaulette, "shoulder ornament on a uniform," 1783, from French épaulette "an epaulet" (16c.), diminutive of épaule "shoulder," from Old French espaule (12c.), from Latin spatula "flat piece of wood, splint," in Medieval Latin "shoulder blade," diminutive of spatha "broad wooden instrument, broad sword," from Greek spathe "a broad flat sword" (see spade (n.1)).
epee (n.): 1889, from French épée, literally "sword" from Old French espe (9c., spede) "spear, lance," from Latin spatha (see epaulet).
epeiric (adj.): in reference to seas covering continental shelves, 1915, from Greek epeiros "mainland, land, continent," from PIE root *apero- "shore" (source also of Old English ofer "bank, rim, shore," Old Frisian over "bank") + -ic.
As the term "continental deposits" in this sense is now ingrained in Geology, we can no longer use Dana's "continental seas" without raising a question in the mind as to what is meant when their deposits are considered. For this reason we propose here to use epeiric seas (meaning seas that lie upon the continents) for the bodies of water that lie within the continents in the downwarps of the continental masses. [Louis V. Pirsson, "A Text-Book of Geology," 1915]
epexegesis (n.): "words added to convey more clearly the meaning intended," 1620s, from Modern Latin, from Greek epexegesis "a detailed account, explanation," from epi "in addition" (see epi-) + exegeisthai "to explain" (see exegesis). Related: Epexegetic; epexegetical.
ephah (n.): Hebrew dry measure, probably of Egyptian origin (compare Coptic epi "measure").
ephebe (n.): "young man," 1690s, from Greek ephebos (see ephebic).