effervescent (adj.) Look up effervescent at Dictionary.com
1680s, from Latin effervescentem (nominative effervescens), present participle of effervescere (see effervescence). Meaning "exuberant" is from 1833.
effete (adj.) Look up effete at Dictionary.com
1620s, from Latin effetus (usually in fem. effeta) "exhausted, unproductive, worn out (with bearing offspring), past bearing," literally "that has given birth," from a lost verb, *efferi, from ex- "out" (see ex-) + fetus "childbearing, offspring" (see fetus). Figurative use is earliest in English; literal use is rare. Sense of "exhausted" is 1660s; that of "intellectually or morally exhausted" (1790) led to "decadent" (19c.).
efficacious (adj.) Look up efficacious at Dictionary.com
"sure to have the desired effect" (often of medicines), 1520s, from Latin efficaci-, stem of efficax (see efficacy) + -ous. Related: Efficaciously; efficaciousness.
efficacy (n.) Look up efficacy at Dictionary.com
1520s, from Latin efficacia "efficacy, efficiency," from efficax (genitive efficacis) "powerful, effective," from stem of efficere "work out, accomplish" (see effect). Earlier in same sense was efficace (c.1200), from Old French eficace (14c.), from Latin efficacia; also efficacite (early 15c.), from Latin efficacitatem.
efficiency (n.) Look up efficiency at Dictionary.com
1590s, "power to accomplish something," from Latin efficientia (from efficientem; see efficient) + -cy. In mechanics, "ratio of useful work done to energy expended," from 1858. Attested from 1952 as short for efficiency apartment (itself from 1930).
efficient (adj.) Look up efficient at Dictionary.com
"capable of producing the desired effect," late 14c., "making, producing immediate effect," from Old French efficient and directly from Latin efficientem (nominative efficiens) "effective, efficient, producing, active," present participle of efficere "work out, accomplish" (see effect). Meaning "productive, skilled" is from 1787. Related: Efficiently.
effigy (n.) Look up effigy at Dictionary.com
1530s, "image of a person," from Middle French effigie (13c.), from Latin effigies "copy or imitation of something, likeness," from or related to effingere "mold, fashion, portray," from ex- "out" (see ex-) + fingere "to form, shape" (see fiction). The Latin word was regarded as plural and the -s was lopped off by 18c. Specifically associated with burning, hanging, etc., at least since 1670s.
effleurage (n.) Look up effleurage at Dictionary.com
1886, from French effleurage, from effleurer "to touch lightly."
effloresce (v.) Look up effloresce at Dictionary.com
"to come into flower," 1775, from Latin efflorescere "to blossom, spring up, flourish, abound," from ex "out" (see ex-) + florescere "to blossom," from flos (see flora).
efflorescence (n.) Look up efflorescence at Dictionary.com
1620s, from French efflorescence, from Latin efflorescentem (nominative efflorescens), present participle of efflorescere (see effloresce).
efflorescent (adj.) Look up efflorescent at Dictionary.com
1818, from Latin efflorescentem (nominative efflorescens), present participle of efflorescere (see effloresce).
effluence (n.) Look up effluence at Dictionary.com
c.1600, from Late Latin effluentia, from Latin effluentem (nominative effluens) "flowing out," present participle of effluere "to flow out," from ex- "out" (see ex-) + fluere "to flow" (see fluent).
effluent (adj.) Look up effluent at Dictionary.com
mid-15c., from Latin effluentem (see effluence). As a noun, from 1859; meaning "liquid industrial waste" is from 1930.
effluvia (n.) Look up effluvia at Dictionary.com
Latin plural of effluvium.
effluvium (n.) Look up effluvium at Dictionary.com
1640s, from Latin effluvium "a flowing out," from effluere (see effluence).
efflux (n.) Look up efflux at Dictionary.com
1640s, from Latin effluxus, past participle of effluere (see effluence).
effort (n.) Look up effort at Dictionary.com
late 15c., from Middle French effort, noun of action from Old French esforz "force, impetuosity, strength, power," back-formation from esforcier "force out, exert oneself," from Vulgar Latin *exfortiare "to show strength" (source of Italian sforza), from Latin ex- "out" (see ex-) + Latin fortis "strong" (see fort).
Effort is only effort when it begins to hurt. [Ortega y Gasset, 1949]
Related: Efforts.
effortless (adj.) Look up effortless at Dictionary.com
1801, "passive," from effort + -less. Meaning "easy" is from 1831. Related: Effortlessly; effortlessness.
effrontery (n.) Look up effrontery at Dictionary.com
1715, from French effronterie, from effronté "shameless," from Old French esfronte "shameless, brazen," probably from Late Latin effrontem (nominative effrons) "barefaced," from Latin ex- "out" (see ex-) + frontem (nominative frons) "brow" (see front (n.)).

Latin frontus had a sense of "ability to blush," but the literal sense of effrontery often has been taken to be "putting forth the forehead." Forehead in Johnson's Dictionary (1755) has a secondary sense of "impudence; confidence; assurance; audaciousness; audacity."
effulgence (n.) Look up effulgence at Dictionary.com
1660s, from Late Latin effulgentia (from Latin effulgentum; see effulgent) + -ce.
effulgent (adj.) Look up effulgent at Dictionary.com
1738, back-formation from effulgence, or else from Latin effulgentem (nominative effulgens), present participle of effulgere, from ex "out" (see ex-) + fulgere "to shine" (see bleach (v.)).
effuse (v.) Look up effuse at Dictionary.com
late 14c., from Middle French effuser or directly from Latin effusus, past participle of effundere "to pour forth" (see effusion). Related: Effused; effusing.
effusion (n.) Look up effusion at Dictionary.com
c.1400, "a pouring out," from Middle French effusion (14c.) and directly from Latin effusionem (nominative effusio) "a pouring forth," noun of action from past participle stem of effundere "pour forth, spread abroad," from ex- "out" (see ex-) + fundere "pour" (see found (v.2)). Figuratively, of speech, emotion, etc., from 1650s.
effusive (adj.) Look up effusive at Dictionary.com
1660s, from Latin effus-, stem of effundere (see effusion) + -ive. Related: Effusively.
eft (n.) Look up eft at Dictionary.com
Old English efte, efeta "small lizard-like animal," of unknown origin (see newt).
eftsoons (adv.) Look up eftsoons at Dictionary.com
obsolete or archaic way of saying "soon afterward," from Old English eftsona "a second time, repeatedly, soon after, again," from eft "afterward, again, a second time" (from Proto-Germanic *aftiz, from PIE root *apo- "off, away;" see apo-) + sona "immediately" (see soon). Not in living use since 17c.
egad Look up egad at Dictionary.com
1670s, I gad, a softened oath, second element God, first uncertain; perhaps it represents exclamation ah.
egalitarian (adj.) Look up egalitarian at Dictionary.com
1885, from French égalitaire, from Old French egalite, from Latin aequalitatem (see equality). The noun is 1920.
egalitarianism (n.) Look up egalitarianism at Dictionary.com
1932, from egalitarian + -ism.
Egbert Look up Egbert at Dictionary.com
masc. proper name, from Old English Ecg-beorht, literally "sword-bright." See edge (n.) + bright (adj.).
egest (v.) Look up egest at Dictionary.com
c.1600, from Latin egestus, past participle of egere, from ex- "out" (see ex-) + gere "to carry." Related: Egested; egesting.
egestion (n.) Look up egestion at Dictionary.com
early 15c., from Latin egestionem (nominative egestio), noun of action from past participle stem of egere (see egest).
egg (n.) Look up egg at Dictionary.com
mid-14c., from northern England dialect, from Old Norse egg, which vied with Middle English eye, eai (from Old English æg) until finally displacing it after 1500; both are from Proto-Germanic *ajja(m) (cognates: Old Saxon, Middle Dutch, Dutch, Old High German, German ei, Gothic ada), probably from PIE *owyo-/*oyyo- "egg" (cognates: Old Church Slavonic aja, Russian jajco, Breton ui, Welsh wy, Greek oon, Latin ovum); possibly derived from root *awi- "bird." Caxton (15c.) writes of a merchant (probably a north-country man) in a public house on the Thames who asked for eggs:
And the goode wyf answerde, that she coude speke no frenshe. And the marchaunt was angry, for he also coude speke no frenshe, but wolde have hadde egges, and she understode hym not.
She did, however, recognize another customer's request for "eyren." Bad egg in the figurative sense is from 1855. To have egg on (one's) face "be made to look foolish" is attested by 1948.
[Young & Rubincam] realize full well that a crew can sometimes make or break a show. It can do little things to ruin a program or else, by giving it its best, can really get that all-important rating. They are mindful of an emcee of a variety show who already has been tabbed "old egg in your face" because the crew has managed to get him in such awkward positions on the TV screen. ["Billboard," March 5, 1949]
Eggs Benedict attested by 1898. The figure of speech represented in to have all (one's) eggs in one basket is attested by 1660s.
egg (v.) Look up egg at Dictionary.com
c.1200, from Old Norse eggja "to goad on, incite," from egg "edge" (see edge (n.)). The unrelated verb meaning "to pelt with (rotten) eggs" is from 1857, from egg (n.). Related: Egged; egging.
egg-beater (n.) Look up egg-beater at Dictionary.com
also eggbeater, 1828, from egg (n.) + beater. Slang sense of "helicopter" is from 1937 from notion of whirling rotation.
egghead (n.) Look up egghead at Dictionary.com
1907, "bald person," from egg (n.) + head (n.). Sense of "intellectual" is attested from 1918, among Chicago newspapermen; popularized by U.S. syndicated columnist Stewart Alsop in 1952 in reference to Adlai Stevenson's presidential campaign.
Adlai Stevenson once told what it was like to be the rare intellectual in politics. "Via ovicapitum dura est," he said, the way of the egghead is hard. [New York Times, Oct. 28, 1982]
eggnog (n.) Look up eggnog at Dictionary.com
also egg nog, c.1775, American English, from egg (n.) + nog "strong ale."
eggplant (n.) Look up eggplant at Dictionary.com
1767, from egg (n.) + plant (n.). Originally of the white variety. Compare aubergine.
eggshell (n.) Look up eggshell at Dictionary.com
early 15c., from egg (n.) + shell (n.). Earlier ay-schelle (c.1300). Emblematic of "thin and delicate" from 1835; as a color term, from 1894. The figure of treading on eggshells "to move cautiously" is attested by 1734.
eglantine (n.) Look up eglantine at Dictionary.com
"sweet briar," c.1400, from French églantine, from Old French aiglent "dog rose," from Vulgar Latin *aquilentus "rich in prickles," from Latin aculeus "spine, prickle," diminutive of acus "needle" (see acuity).
ego (n.) Look up ego at Dictionary.com
1714, as a term in metaphysics, from Latin ego "I" (cognate with Old English ic, see I). Psychoanalytic sense is from 1894; sense of "conceit" is 1891. Ego trip first recorded 1969.
In the book of Egoism it is written, Possession without obligation to the object possessed approaches felicity. [George Meredith, "The Egoist," 1879]
egocentric (adj.) Look up egocentric at Dictionary.com
1900, from ego + -centric. Related: Egocentricity; egocentrism.
egoism (n.) Look up egoism at Dictionary.com
1785, in metaphysics (see egoist), from French égoisme (1755), from Modern Latin egoismus, from Latin ego (see ego). Meaning "self-interest" is from 1800.
egoist (n.) Look up egoist at Dictionary.com
1785, in metaphysics, "one who maintains there is no evidence of the existence of anything but the self" (taking ego in a sense of "thinking subject"), from French égoiste (1755); see ego + -ist. Meaning "selfish person" is from 1879. Related: Egoistic; egoistical.
egomania (n.) Look up egomania at Dictionary.com
1825, from ego + mania.
egomaniac (n.) Look up egomaniac at Dictionary.com
1890, from egomania. Related: Egomaniacal.
egotism (n.) Look up egotism at Dictionary.com
1714, from ego + -ism (see egotist). Meaning "selfishness" is from 1800.
egotist (n.) Look up egotist at Dictionary.com
1714, first used by Joseph Addison; see ego + -ist. Addison credits the term to "Port-Royalists" who used it in reference to obtrusive use of first person singular pronoun in writing, hence "talking too much about oneself." Meaning "self-conceit, selfishness" is 1800. The -t- is abnornmal, perhaps by influence of dogmatism. Related: Egotistic; egotistical.
egregious (adj.) Look up egregious at Dictionary.com
1530s, "distinguished, eminent, excellent," from Latin egregius "distinguished, excellent, extraordinary," from the phrase ex grege "rising above the flock," from ex "out of" (see ex-) + grege, ablative of grex "herd, flock" (see gregarious).

Disapproving sense, now predominant, arose late 16c., originally ironic and is not in the Latin word, which etymologically means simply "exceptional." Related: Egregiously; egregiousness.
egress (n.) Look up egress at Dictionary.com
1530s, from Latin egressus "a going out," noun use of past participle of egredi "go out," from ex- "out" (see ex-) + -gredi, comb. form of gradi "step, go" (see grade (n.)). Perhaps a back-formation from egression (early 15c.).