Online Etymology Dictionary

ecosphere (n.): 1953, the region around a star where conditions allow life-bearing planets to exist; see eco- + sphere. Apparently coined by German-born U.S. physician and space medicine pioneer Hubertus Strughold (1898-1986).
ecosystem (n.): 1935; see eco- + system. Perhaps coined by English ecologist Sir Arthur George Tansley (1871-1955).
ecotourism (n.): by 1989, from eco- + tourism. Related: Ecotourist.
ecru (adj.): 1869, from French écru "raw, unbleached," from Old French escru "raw, crude, rough" (13c.), from es- "thoroughly" (see ex-) + Latin crudus "raw" (see crude).
ecstasy (n.): late 14c., "in a frenzy or stupor, fearful, excited," from Old French estaise "ecstasy, rapture," from Late Latin extasis, from Greek ekstasis "entrancement, astonishment; any displacement," in New Testament "a trance," from existanai "displace, put out of place," also "drive out of one's mind" (existanai phrenon), from ek "out" (see ex-) + histanai "to place, cause to stand," from PIE root *sta- "to stand" (see stet).

Used by 17c. mystical writers for "a state of rapture that stupefied the body while the soul contemplated divine things," which probably helped the meaning shift to "exalted state of good feeling" (1610s). Slang use for the drug 3,4-methylendioxymethamphetamine dates from 1985.
ecstatic (adj.): 1590s, "mystically absorbed, stupefied," from Greek ekstatikos "unstable," from ekstasis (see ecstatic). Meaning "characterized by intense emotions" is from 1660s, now usually pleasurable ones, but not originally always so. Related: Ecstatical; ecstatically.
ecto-: word-forming element generally meaning "outside, external," before vowels ect-, comb. form of Greek ektos "outside" (adv.), used to form scientific compounds in Greek; related to Greek ek, ex "out," from PIE *eghs- (see ex-).
ectoderm (n.): 1861, from ecto- + -derm. Coined by Prussian embryologist Robert Remak (1815-1865).
ectomorph (n.): 1940, coined by Sheldon from ecto- + Greek morphe (see morphine). Related: Ectomorphic.
ectopic (adj.): 1873, from ectopia (1847), coined in Modern Latin from Greek ektopos "away from a place," from ek- "out" (see ex-) + topos "place" (see topos).
ectoplasm (n.): 1883, of amoebas, 1901, of spirits, from ecto- + -plasm.
ecu (n.): old French silver coin, 1704, from French écu, from Old French escu (12c.) "shield, coat of arms," also the name of a coin, from Latin scutum "shield" (see hide (n.1)). First issued by Louis IX (1226-1270); so called because the shield of France was imprinted on them.
Ecuador: from the Spanish form of equator (which runs through it). Before 1830 the region bore the name of its chief city, Quito, which is from the name of a now-extinct native people, of unknown meaning. Related: Ecuadorian; Ecuadorean.
ecumenical (adj.): late 16c., "representing the entire (Christian) world," formed in English as an ecclesiastical word, from Late Latin oecumenicus "general, universal," from Greek oikoumenikos, from he oikoumene ge "the inhabited world (as known to the ancient Greeks); the Greeks and their neighbors considered as developed human society," from oikoumenos, present passive participle of oikein "inhabit," from oikos "house, habitation" (see villa).
ecumenism (n.): 1948, from ecumen- (see ecumenical) + -ism.
eczema (n.): 1753, from Greek ekzema, literally "something thrown out by heat," from ekzein "to boil out," from ek "out" (see ex-) + zema "boiling," from zein "to boil," from PIE root *yes- "to boil, foam, bubble" (see yeast). Said to have been the name given by ancient physicians to "any fiery pustule on the skin."
edacious (adj.): 1829, from Latin edaci-, stem of edax "voracious, gluttonous," from edere "to eat" (see edible) + -ous. Related: Edacity (1620s).
Edam: 1836, cheese named for Edam, village in Holland where it was originally made. The place name is literally "the dam on the River Ye," which flows into the Ijsselmeer there, and the river name is literally "river" (cf. ea).
Edda (n.): 1771, by some identified with the name of the old woman in the Old Norse poem "Rigsþul," by others derived from Old Norse oðr "spirit, mind, passion, song, poetry" (cognate with Old Irish faith "poet," Welsh gwawd "poem," Old English woþ "sound, melody, song," Latin vates "seer, soothsayer;" see wood (adj.)).

It is the name given to two Icelandic books, the first a miscellany of poetry, mythology, and grammar by Snorri Sturluson (d.1241), since 1642 called the Younger or Prose Edda; and a c.1200 collection of ancient Germanic poetry and religious tales, called the Elder or Poetic Edda.
eddy (n.): mid-15c., Scottish ydy, possibly from Old Norse iða "whirlpool," from Proto-Germanic *ith- "a second time, again," which is related to the common Old English prefix ed- "again, backwards; repetition, turning" (forming such words as edðingung "reconciliation," edgift "restitution," edniwian "to renew, restore," edhwierfan "to retrace one's steps," edgeong "to become young again"). Cf. Old English edwielle "eddy, vortex, whirlpool." The prefix is cognate with Latin et, Old High German et-, Gothic iþ "and, but, however." Related: Eddies.
eddy (v.): 1810, from eddy (n.). Related: Eddied; eddying.
edelweiss (n.): 1862, from German Edelweiß, literally "noble white," from Old High German edili "noble" (see atheling) + German weiss "white" (see white).
edema (n.): c.1400, from medical Latin, from Greek oidema (genitive oidematos) "a swelling tumor," from oidein "to swell," from oidos "tumor, swelling," from PIE *oid- "to swell;" cf. Latin aemidus "swelling," Armenian aitumn "a swelling," Old Norse eista "testicle," Old English attor "poison" (that which makes the body swell), and the first element in Oedipus.
Eden (n.): early 13c., "delightful place," figurative use of the place described in Genesis, usually referred to Hebrew edhen "pleasure, delight," but perhaps from Ugaritic base 'dn and meaning "a place that is well-watered throughout" (see also Aden).
Edgar: masc. proper name, from Old English Ead-gar, literally "prosperity-spear," from ead "prosperity" + gar (see gar).
edge (n.): Old English ecg "corner, edge, point," also "sword" (cf. ecgplega, literally "edge play," ecghete, literally "edge hate," both used poetically for "battle"), from Proto-Germanic *agjo (cf. Old Frisian egg "edge;" Old Saxon eggia "point, edge;" Middle Dutch egghe, Dutch eg; Old Norse egg, see egg (v.); Old High German ecka, German Eck "corner"), from PIE root *ak- "sharp, pointed" (cf. Sanskrit asrih "edge," Latin acies, Greek akis "point;" see acrid).

Spelling development of Old English -cg to Middle English -gg to Modern English -dge represents a widespread shift in pronunciation. To get the edge on (someone) is U.S. colloquial, first recorded 1911. Edge city is from Joel Garreau's 1992 book of that name. Razor's edge as a perilous narrow path translates Greek epi xyrou akmes. To have (one's) teeth on edge is from late 14c., though "It is not quite clear what is the precise notion originally expressed in this phrase" [OED].
edge (v.): late 13c., "to give an edge to" (implied in past participle egged), from edge (n.). Meaning "to move edgeways (with the edge toward the spectator), advance slowly" is from 1620s, originally nautical. Meaning "to defeat by a narrow margin" is from 1953. The meaning "urge on, incite" (16c.) often must be a mistake for egg (v.). Related: Edged; edging.
edgeways: also edge-ways, 1560s, from edge (n.) + -ways. First attested form of the word is edgewaie; the adv. genitive -s appears by 1640s. Edgewise (1715) appears to be a variant, based on otherwise, etc. See edge (v.).
As if it were possible for any of us to slide in a word edgewise! [Mary Mitford, "Our Village," 1824].
To edge in a word in this sense is from 1680s.
edgewise: see edgeways.
edging (n.): 1570s, "the putting of a border," verbal noun from edge (v.). Meaning "a border" is from 1660s; that of "the trimming of lawn edges" is from 1858.
edgy (adj.): "having sharp edges," 1755, from edge (n.) + -y (2). Meaning "tense and irritable" is attested by 1837, perhaps from notion of being on the edge, at the point of doing something irrational (a figurative use attested from c.1600).
edible (adj.): 1590s, from Late Latin edibilis "eatable," from Latin edere "to eat," from PIE root *ed- "to eat" (cf. Sanskrit admi "I eat;" Greek edo "I eat;" Lithuanian edu "I eat;" Hittite edmi "I eat," adanna "food;" Old Irish ithim "I eat;" Gothic itan, Old Swedish and Old English etan, Old High German essan "to eat;" Avestan ad- "to eat;" Armenian utem "I eat;" Old Church Slavonic jasti "to eat," Russian jest "to eat").
edict (n.): late 15c., edycte; earlier edit, late 13c., "proclamation having the force of law," from Old French edit, from Latin edictum "proclamation, ordinance, edict," neuter past participle of edicere "publish, proclaim," from e- "out" (see ex-) + dicere "to say" (see diction).
edification (n.): mid-14c., in religious use, "building up of the soul," from Old French edification and directly from Latin aedificationem (nominative aedificatio) "construction, building," in Late Latin "spiritual improvement," from past participle stem of aedificare (see edifice). Religious use is as translation of Greek oikodome in I Cor. xiv. Meaning "mental improvement" is 1650s. Literal sense of "building" is rare in English.
edifice (n.): late 14c., from Old French edifice "building," from Latin aedificium "building," from aedificare "to erect a building," from aedis, variant of aedes "temple, sanctuary," usually a single edifice without partitions, also, in the plural, "dwelling house, building," originally "a place with a hearth" + the root of facere "to make" (see factitious).

Ædis is from PIE *aidh- "to burn" (cf. Greek aithein "to burn," Sanskrit inddhe "burst into flames," Old Irish aed "fire," Welsh aidd "heat, zeal," Old High German eit "funeral pile"), from root *ai- "to burn."
edify (v.): mid-14c., "to build, construct," also, in figurative use, "to build up morally or in faith," from Old French edefiier "build, install, teach, instruct (morally)," from Latin aedificare "to build, construct," in Late Latin "improve spiritually, instruct" (see edifice). Related: Edified; edifying.
Edinburgh: older than King Edwin of Northumbria (who often is credited as the source of the name); originally Din Eidyn, Celtic, perhaps literally "fort on a slope." Later the first element was trimmed off and Old English burh "fort" added in its place." Dunedin in New Zealand represents an attempt at the original form.
edit (v.): 1791, perhaps a back-formation from editor, or from French éditer, or from Latin editus, past participle of edere (see edition). Related: Edited; editing. As a noun, by 1960.
Edith: fem. proper name, Old English Eadgyð, from ead "wealth, prosperity, happiness" + guð "war." A fairly common name; it survived through the Middle Ages, probably on the popularity of St. Eadgyð of Wilton (962-84, abbess, daughter of King Edgar of England), fell from favor 16c., was revived in fashion 19c.
edition (n.): early 15c., "version, translation, a form of a literary work;" 1550s, "act of publishing," from French édition or directly from Latin editionem (nominative editio) "a bringing forth, producing," also "a statement, account," from past participle stem of edere "bring forth, produce," from ex- "out" (see ex-) + -dere, comb. form of dare "to give" (see date (n.1)). "It is awkward to speak of, e.g. 'The second edition of Campbell's edition of Plato's "Theætetus"'; but existing usage affords no satisfactory substitute for this inconvenient mode of expression" [OED].
editor (n.): 1640s, "publisher," from Latin editor "one who puts forth," agent noun from editus, past participle of edere (see edition). By 1712 in sense of "person who prepares written matter for publication;" specific sense in newspapers is from 1803.
editorial (adj.): 1741; see editor + -al (2). Noun meaning "newspaper article by an editor," is from 1830, American English, from the adjective in reference to such writings (1802). Related: Editorially.
editorialize (v.): "introduce opinions into factual accounts," 1856, from editorial + -ize. Related: Editorialized; editorializing.
Edmund: masc. proper name, Old English Eadmund, literally "prosperity-protector." The second element is related to Latin manus "hand" (see manual (adj.)).
Edna: fem. proper name, from Greek, from Hebrew ednah "delight" (see Eden). Related to Arabic ghadan "luxury." Among the top 20 names for girls born in the U.S. every year from 1889 to 1917.
Edsel: the make of car was introduced 1956, named for Henry and Clara Ford's only child; figurative sense of "something useless and unwanted" is almost as old. Edsel is a family name, attested since 14c. (William de Egeshawe), from High Edser in Ewhurst, Surrey.
educable (adj.): 1842 (implied in educability); see educate + -able.
educate (v.): mid-15c., "bring up (children), train," from Latin educatus, past participle of educare "bring up, rear, educate," which is related to educere "bring out, lead forth," from ex- "out" (see ex-) + ducere "to lead" (see duke (n.)). Meaning "provide schooling" is first attested 1580s. Related: Educated; educating.
educated (adj.): 1660s, past participle adjective from educate (v.). As an abbreviated way to say well-educated, attested from 1855. Educated guess first attested 1954.
education (n.): 1530s, "childrearing," also "the training of animals," from Middle French education (14c.) and directly from Latin educationem (nominative educatio), from past participle stem of educare (see educate). Originally of education in social codes and manners; meaning "systematic schooling and training for work" is from 1610s.