Online Etymology Dictionary

Eblis: prince of the fallen angels in Arabic mythology and religion, from Arabic Iblis. Klein thinks this may be Greek diablos, passed through Syriac where the first syllable was mistaken for the Syriac genitive particle di and dropped.
ebola (n.): virus, 1976, named for Ebola River valley in Congo, where it first was studied.
ebon: "ebony wood, ebony tree," mid-15c.; see ebony. Figurative sense of "dark, black" is from 1590s; in some cases a poetic shortening of ebony.
Ebonics: "African-American vernacular English," 1975, as title of a book by U.S. professor R.L. Williams (b.1930); a blend of ebony and phonics.
ebony (n.): 1590s, from hebenyf (late 14c.), perhaps a Middle English misreading of Latin hebeninus "of ebony," from Greek ebeninos, from ebenos "ebony," probably from Egyptian hbnj or another Semitic source. Figurative use to suggest intense blackness is from 1620s. As an adjective, from 1590s. French ébène, Old High German ebenus (German Ebenholz) are from Latin ebenus.
ebriety (n.): "state or habit of being intoxicated," 1580s, from French ébriété, from Latin ebrietatem (nominative ebrietas) "drunknenness," from ebrius "drunk, full, sated with drink," of unknown origin. The opposite of sobriety. Related: Ebrious.
ebullience (n.): 1749, from Latin ebullientem, present participle of ebullire (see ebullient + -ence). Related: Ebulliency (1670s).
ebullient (adj.): 1590s, "boiling," from Latin ebullientem (nominative ebulliens), present participle of ebullire "to boil over," literally and figuratively, from ex- "out" (see ex-) + bullire "to bubble" (see boil (v.)). Figurative sense of "enthusiastic" is first recorded 1660s.
ec-: typical form in English of Latin ex-, Greek ex-, ek- before consonants. See ex-.
ecarte (n.): card game for two played with 32 cards, 1824, from French écarté, literally "discarded," past participle of écarter "to discard," from e- (see ex-) + carte (see card (n.)).
ecce homo: Latin, literally "behold the man" (John xix:5).
eccentric: early 15c. (n.) "eccentric circle or orbit," 1550s (adj.), originally a term in Ptolemaic astronomy, "circle or orbit not having the Earth precisely at its center," from Middle French eccentrique and directly from Medieval Latin eccentricus (noun and adjective), from Greek ekkentros "out of the center" (as opposed to concentric), from ek "out" (see ex-) + kentron "center" (see center (n.)). Figurative sense of "odd, whimsical" (adj.) first recorded 1620s. Noun meaning person with such qualities first attested 1832.
eccentricity (n.): 1540s, of planetary orbits; 1650s, of persons (an instance of eccentricity); 1794, of persons (a quality of eccentricity); from eccentric + -ity. Related: Eccentricities.
Ecclesiastes (n.): c.1300, name given to one of the Old Testament books, traditionally ascribed to Solomon, from Greek ekklesiastes (see ecclesiastic), to render Hebrew qoheleth "one who addresses an assembly," from qahal "assembly." The title is technically the designation of the speaker, but that word throughout is usually rendered into English as "The Preacher" (which Klein calls "erroneous").
ecclesiastic (adj.): late 15c., from Middle French ecclésiastique and directly from Late Latin ecclesiasticus, from Greek ekklesiastikos "of the (ancient Athenian) assembly," later, "of the church," from ekklesiastes "speaker in an assembly or church, preacher," from ekkalein "to call out," from ek "out" (see ex-) + kalein "to call" (see claim (v.)).
ecclesiastical (adj.): early 15c., from ecclesiastic + -al (1). Related: Ecclesiastically.
ecdysiast (n.): H.L. Mencken's invented proper word for "strip-tease artist," 1940, from Greek ekdysis "a stripping or casting off" (used scientifically with reference to serpents shedding skin or crustacea molting), from ekdyein "to put off" (contrasted with endyo "to put on"), from ek (see ex-) + dyein "to enter, to put on."
echelon (n.): 1796, "step-like arrangement of troops," from French échelon "level, echelon," literally "rung of a ladder," from Old French eschelon, from eschiele "ladder," from Late Latin scala "stair, slope," from Latin scalae (plural) "ladder, steps," from PIE *skand- "to spring, leap" (see scan). Sense of "level, subdivision" is from WWI.
echidna (n.): Australian egg-laying hedgehog-like mammal, 1847, usually explained as from Greek ekhidna "snake, viper," from ekhis "snake," from PIE *angwhi- "snake, eel" (cf. Norwegian igle, Old High German egala, German Egel "leech," Latin anguis "serpent, snake").

But this sense is difficult to reconcile with this animal (unless it is a reference to the ant-eating tongue), and the name seems more properly to belong to Latin echinus, Greek ekhinos "sea-urchin," originally "hedgehog" (in Greek also "sharp points"), which Watkins explains as "snake-eater," from ekhis "snake."
echinoderm (n.): 1835, from Modern Latin Echinodermata, name of the phylum that includes starfish and sea urchins, from Greek ekhinos "sea urchin," originally "porcupine, hedgehog" (see echidna) + derma (genitive dermatos) "skin" (see derma); so called from its spiky shell.
echo (n.): mid-14c., from Latin echo, from Greek echo, personified as a mountain nymph, from or related to ekhe "sound," ekhein "to resound," from PIE root *swagh- "to resound" (cf. Sanskrit vagnuh "sound," Latin vagire "to cry," Old English swogan "to resound"). Related: Echoes.
echo (v.): 1550s, from echo (n.). Related: Echoed; echoing.
echoic (adj.): 1880; see echo (n.) + -ic.
echolalia (n.): 1885, from Greek ekho (see echo (n.)) + lalia "talk, prattle, a speaking," from lalein "to speak, prattle," of echoic origin.
echolocation (n.): 1944, from echo (n.) + location.
echopraxia (n.): 1904, from Greek ekho (see echo (n.)) + praxis "action" (see praxis).
echovirus (n.): also ECHO virus, 1955, acronym for enteric cytopathogenic human orphan; "orphan" because when discovered they were not known to cause any disease.
eclair (n.): 1861, from French éclair, literally "lightning," from Old French esclair "light, daylight, flash of light," from esclairare "to light up, make shine" (12c.), ultimately from Latin exclarare "light up, illumine," from ex- "out" (see ex-) + clarus "clear" (see clear (adj.)).
eclat (n.): 1670s, "showy brilliance," from French éclat "splinter, fragment" (12c.), also "flash of brilliance," from eclater "burst out, splinter," from Old French esclater "smash, shatter into pieces," of uncertain origin, perhaps from a West Germanic word related to slit or to Old High German sleizen "tear to pieces; to split, cleave." Extended sense of "conspicuous success" is first recorded in English in 1741.
eclectic (adj.): 1680s, originally in reference to a group of ancient philosophers who selected doctrines from every system; from French eclectique (1650s), from Greek eklektikos "selective," literally "picking out," from eklektos "selected," from eklegein "pick out, select," from ek "out" (see ex-) + legein "gather, choose" (see lecture (n.)). Broader sense of "borrowed from diverse sources" is first recorded 1847. As a noun from 1817.
eclecticism (n.): 1798, from eclectic + -ism.
eclipse (n.): late 13c., from Old French eclipse "eclipse, darkness" (12c.), from Latin eclipsis, from Greek ekleipsis "an abandonment, an eclipse," from ekleipein "to forsake a usual place, fail to appear, be eclipsed," from ek "out" (see ex-) + leipein "to leave" (cognate with Latin linquere; see relinquish).
eclipse (v.): late 14c. (intransitive, a sense now obsolete), from eclipse (n.). Transitive use from late 15c.; figurative use from 1580s. Related: Eclipsed; eclipsing.
ecliptic (n.): late 14c., "the circle in the sky followed by the Sun," from Medieval Latin ecliptica, from Late Latin (linea) ecliptica, from Greek ekliptikos "of an eclipse" (see eclipse (n.)). So called because eclipses happen only when the Moon is near the line. Related: Ecliptical.
eclogue (n.): "short poem," especially a pastoral dialogue, mid-15c., from Latin ecloga "selection, short poem, eclogue," from Greek ekloge "selection," from eklegein "to select" (see eclectic).
eco-: word-forming element referring to the environment and man's relation to it, abstracted from ecology, ecological; attested from 1969.
ecocentric (adj.): also eco-centric, by 1975, from eco- + -centric.
ecofriendly (adj.): also eco-friendly, by 1993, from eco- + friendly.
ecological (adj.): 1899, see ecology + -ical. Related: Ecologically.
ecologist (n.): 1893, see ecology + -ist.
ecology (n.): 1873, "branch of science dealing with the relationship of living things to their environments, coined by German zoologist Ernst Haeckel (1834-1919) as Okologie, from Greek oikos "house, dwelling place, habitation" (see villa) + -logia "study of" (see -logy). In use with reference to anti-pollution activities from 1960s.
econometric (adj.): 1933, from comb. form of economy + -metric.
economic (adj.): 1590s, "pertaining to management of a household," perhaps shortened from economical or from French économique or directly from Latin oeconomicus "of domestic economy," from Greek oikonomikos "practiced in the management of a household or family," hence, "frugal, thrifty," from oikonomia (see economy (n.)). Meaning "relating to the science of economics" is from 1835 and now is the main sense, economical retaining the older one of "characterized by thrift."
economical (adj.): 1570s, "pertaining to household management; from economic + -al (1). Meaning "pertaining to political economy" is from 1781; that of "thrifty" is from 1780. Related: Economically.
economics (n.): 1580s, "art of managing a household," perhaps from French économique (see economic); also see -ics. Meaning "science of wealth" is from 1792.
economist (n.): 1580s, "household manager," from Middle French économiste; meaning "student of political economy" is from 1804; see economy + -ist.
economize (v.): 1640s, "to govern a household," from economy + -ize. Meaning "to spend less" is from 1790. Related: Economized; economizing; economization; economizer.
economy (n.): 1530s, "household management," from Latin oeconomia, from Greek oikonomia "household management, thrift," from oikonomos "manager, steward," from oikos "house" (cognate with Latin vicus "district," vicinus "near;" Old English wic "dwelling, village;" see villa) + nomos "managing," from nemein "manage" (see numismatics). The sense of "wealth and resources of a country" (short for political economy) is from 1650s.
economy (adj.): as a term in advertising, at first meant simply "cheaper" (1821), then "bigger and thus cheaper per unit or amount" (1950). See economy (n.).
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).