estoppel (n.) Look up estoppel at Dictionary.com
1530s, from Old French estopail, literally "bung, cork," from estoper (see estop).
estrange (v.) Look up estrange at Dictionary.com
late 15c., from Middle French estrangier "to alienate," from Vulgar Latin *extraneare "to treat as a stranger," from Latin extraneus "foreign" (see strange). Related: Estranged.
estrangement (n.) Look up estrangement at Dictionary.com
1650s, from estrange + -ment.
estrogen (n.) Look up estrogen at Dictionary.com
coined 1927 from estrus + -gen. So called for the hormone's ability to produce estrus.
estrus (n.) Look up estrus at Dictionary.com
1850, "frenzied passion," from Latin oestrus "frenzy, gadfly," from Greek oistros "gadfly, breeze, sting, mad impulse," perhaps from a PIE *eis, forming words denoting passion (cognates: Avestan aešma- "anger," Lithuanian aistra "violent passion," Latin ira "anger"). First attested 1890 with specific meaning "rut in animals, heat." Earliest use (1690s) was for "a gadfly." Related: Estrous (1900).
estuary (n.) Look up estuary at Dictionary.com
1530s, from Latin aestuarium "a tidal marsh or opening," from aestus "boiling (of the sea), tide, heat," from PIE *aidh- "to burn" (see edifice). Related: Estuaries; estuarine.
esurient (adj.) Look up esurient at Dictionary.com
1670s, from Latin esurientem (nominative esuriens), present participle of esurire "to be hungry," from stem of edere "to eat" (see edible). Related: Esurience; esuriency.
et al. Look up et al. at Dictionary.com
also et al, 1883, abbreviation of Latin et alii (masc.), et aliæ (fem.), or et alia (neuter), in any case meaning "and others."
et cetera Look up et cetera at Dictionary.com
also etcetera, early 15c., from Latin et cetera, literally "and the others," from et "and" + neuter of ceteri "the others." The common abbreviation was &c. before 20c., but etc. now prevails.
etagere (n.) Look up etagere at Dictionary.com
1858, from French étagère (15c.), from étage "shelf, story, abode, stage, floor" (11c., Old French estage), from Vulgar Latin *staticum, from Latin statio "station, post, residence" (see station (n.)).
etaoin shrdlu Look up etaoin shrdlu at Dictionary.com
1931, journalism slang, the sequence of characters you get if you sweep your finger down the two left-hand columns of Linotype keys, which is what typesetters did when they bungled a line and had to start it over. It was a signal to cut out the sentence, but sometimes it slipped past harried compositors and ended up in print.
etc. Look up etc. at Dictionary.com
see et cetera.
etch (v.) Look up etch at Dictionary.com
1630s, "to engrave by eating away the surface of with acids," from Dutch etsen, from German ätzen "to etch," from Old High German azzon "cause to bite, feed," from Proto-Germanic *atjanan, causative of *etanan "eat" (see eat). Related: Etched; etching.
etching (n.) Look up etching at Dictionary.com
1630s, action of the verb etch, also "the art of engraving;" 1760s as "a print, etc., made from an etched plate."
eternal (adj.) Look up eternal at Dictionary.com
late 14c., from Old French eternel or directly from Late Latin aeternalis, from Latin aeternus "of an age, lasting, enduring, permanent, endless," contraction of aeviternus "of great age," from aevum "age" (see eon). Related: Eternally.
eternity (n.) Look up eternity at Dictionary.com
late 14c., from Old French eternité (12c.), from Latin aeternitatem (nominative aeternitas), from aeternus (see eternal). In the Mercian hymns, Latin aeternum is glossed by Old English ecnisse.
Ethan Look up Ethan at Dictionary.com
masc. proper name, from Hebrew ethan "strong, permanent, perennial, ever-flowing" (of rivers).
ethane (n.) Look up ethane at Dictionary.com
1873, from ethyl + -ane, the appropriate suffix under Hofmann's system.
ethanol (n.) Look up ethanol at Dictionary.com
1900, contracted from ethane, to which it is the corresponding alcohol, + -ol, here indicating alcohol.
Ethel Look up Ethel at Dictionary.com
fem. proper name, originally a shortening of Old English Etheldred, Ethelinda, etc., in which the first element means "nobility."
Ethelbert Look up Ethelbert at Dictionary.com
Anglo-Saxon masc. proper name, Old English Æðelbryht, literally "nobility-bright;" see atheling + bright (adj.).
Etheldred Look up Etheldred at Dictionary.com
Anglo-Saxon fem. proper name, Old English Æðelðryð, literally "of noble strength" (see Audrey).
ether (n.) Look up ether at Dictionary.com
late 14c., "upper regions of space," from Old French ether and directly from Latin aether "the upper pure, bright air," from Greek aither "upper air; bright, purer air; the sky," from aithein "to burn, shine," from PIE root *aidh- "to burn" (see edifice).

In ancient cosmology, the element that filled all space beyond the sphere of the moon, constituting the substance of the stars and planets. Conceived of as a purer form of fire or air, or as a fifth element. From 17c.-19c., it was the scientific word for an assumed "frame of reference" for forces in the universe, perhaps without material properties. The concept was shaken by the Michelson-Morley experiment (1887) and discarded after the Theory of Relativity won acceptance, but before it went it gave rise to the colloquial use of ether for "the radio" (1899).

The name also was bestowed c.1730 (Frobenius; in English by 1757) on a volatile chemical compound known since 14c. for its lightness and lack of color (its anesthetic properties weren't fully established until 1842).
ethereal (adj.) Look up ethereal at Dictionary.com
1510s, "of the highest regions of the atmosphere," from ether + -al (1); extended sense of "light, airy" is from 1590s. Meaning "spiritlike, immaterial" is from 1640s. Related: Ethereally.
etheric (adj.) Look up etheric at Dictionary.com
1878, "pertaining to ether," from ether + -ic. Related: Etherical (1650s).
ethernet (n.) Look up ethernet at Dictionary.com
1980, from ether + ending as in Internet, etc.
ethic (n.) Look up ethic at Dictionary.com
late 14c., ethik "study of morals," from Old French etique (13c.), from Late Latin ethica, from Greek ethike philosophia "moral philosophy," fem. of ethikos "ethical," from ethos "moral character," related to ethos "custom" (see ethos). Meaning "a person's moral principles" is attested from 1650s.
ethical (adj.) Look up ethical at Dictionary.com
c.1600, "pertaining to morality," from ethic + -al (1). Related: Ethicality; ethically.
ethics (n.) Look up ethics at Dictionary.com
"the science of morals," c.1600, plural of Middle English ethik "study of morals" (see ethic). The word also traces to Ta Ethika, title of Aristotle's work.
Ethiop Look up Ethiop at Dictionary.com
late 14c., from Latin Æthiops "Ethiopian, negro," from Greek Aithiops, perhaps from aithein "to burn" + ops "face" (compare aithops "fiery-looking," later "sunburned").
Who the Homeric Æthiopians were is a matter of doubt. The poet elsewhere speaks of two divisions of them, one dwelling near the rising, the other near the setting of the sun, both having imbrowned visages from their proximity to that luminary, and both leading a blissful existence, because living amid a flood of light; and, as a natural concomitant of a blissful existence, blameless, and pure, and free from every kind of moral defilement. [Charles Anthon, note to "The First Six Books of Homer's Iliad," 1878]
Ethiopia Look up Ethiopia at Dictionary.com
Latin Aethiopia, from Greek Aithiopia, from Aithiops (see Ethiop). The native name is Abyssinia.
ethnic (adj.) Look up ethnic at Dictionary.com
late 15c. (earlier ethnical, early 15c.) "pagan, heathen," from Late Latin ethnicus, from Greek ethnikos "adopted to the genius or customs of a people, peculiar to a people," from ethnos "band of people living together, nation, people," properly "people of one's own kind," from PIE *swedh-no-, suffixed form of root *s(w)e- (see idiom). Earlier in English as a noun, "a heathen, pagan, one who is not a Christian or Jew" (c.1400).

In Septuagint, Greek ta ethne translates Hebrew goyim, plural of goy "nation," especially of non-Israelites, hence "Gentile nation, foreign nation not worshipping the true God" (see goy), and ethnikos is used as "savoring of the nature of pagans, alien to the worship of the true God," and as a noun "the pagan, the Gentile." The classical sense of "peculiar to a race or nation" in English is attested from 1851, a return to the word's original meaning; that of "different cultural groups" is 1935; and that of "racial, cultural or national minority group" is American English 1945. Ethnic cleansing is attested from 1991.
Although the term 'ethnic cleansing' has come into English usage only recently, its verbal correlates in Czech, French, German, and Polish go back much further. [Jerry Z. Muller, "Us and Them: The Enduring Power of Ethnic Nationalism," Foreign Affairs, March/April 2008]
ethnicity (n.) Look up ethnicity at Dictionary.com
"ethnic character," 1953, from ethnic + -ity. Earlier it meant "paganism" (1772).
ethno- Look up ethno- at Dictionary.com
word-forming element meaning "race, culture," from Greek ethnos "people, nation, class, caste, tribe; a number of people accustomed to live together" (see ethnic). Used to form modern compounds in the social sciences.
ethnocentric (adj.) Look up ethnocentric at Dictionary.com
1900, from ethno- + -centric; a technical term in social sciences until it began to be more widely used in the second half of the 20th century. Related: Ethnocentricity; ethnocentrism.
ethnography (n.) Look up ethnography at Dictionary.com
1834, perhaps from German Ethnographie; see ethno- + -graphy "the study of." Related: Ethnographer; ethnographic.
ethnology (n.) Look up ethnology at Dictionary.com
1842, from ethno- + -logy. Related: Ethnologist.
ethology (n.) Look up ethology at Dictionary.com
late 17c., "mimicry," from Latin ethologia, from Greek ethologia, from ethos "character" (see ethos). As a branch of zoology, from 1897.
ethos (n.) Look up ethos at Dictionary.com
revived by Palgrave in 1851 from Greek ethos "moral character, nature, disposition, habit, custom," from suffixed form of PIE root *s(w)e- (see idiom). An important concept in Aristotle (as in "Rhetoric" II xii-xiv).
ethyl (n.) Look up ethyl at Dictionary.com
1838, from German ethyl (Liebig, 1834), from ether + -yl. Ethyl alcohol, under other names, was widely used in medicine by 13c.
ethylene (n.) Look up ethylene at Dictionary.com
1852, from ethyl + -ene, probably suggested by methylene.
etic (adj.) Look up etic at Dictionary.com
1954, coined by U.S. linguist K.L. Pike (1912-2000) from ending of phonetic.
etiolate (v.) Look up etiolate at Dictionary.com
of plants, "grown in darkness," 1791, from French étiolé, past participle of étioler "to blanch" (17c.), perhaps literally "to become like straw," from Norman dialect étule "a stalk," Old French esteule "straw, field of stubble," from Latin stipula "straw" (see stipule). Related: Etiolated.
etiology (n.) Look up etiology at Dictionary.com
"science of causes or causation," 1550s, from Late Latin aetiologia, from Greek aitiologia "statement of cause," from aitia "cause" + -logia "a speaking" (see -logy). Related: Etiologic; etiological.
etiquette (n.) Look up etiquette at Dictionary.com
1750, from French étiquette "prescribed behavior," from Old French estiquette "label, ticket" (see ticket).

The sense development in French perhaps is from small cards written or printed with instructions for how to behave properly at court (compare Italian etichetta, Spanish etiqueta), and/or from behavior instructions written on a soldier's billet for lodgings (the main sense of the Old French word).
Etna Look up Etna at Dictionary.com
volcano in Sicily, from Latin Aetna, from an indigenous Sicilian language, *aith-na "the fiery one," from PIE *ai-dh-, from root *ai- "to burn" (see edifice).
Eton Look up Eton at Dictionary.com
collar (1887), jacket (1881, formerly worn by the younger boys there), etc., from Eton College, public school for boys on the Thames opposite Windsor, founded by Henry VI. The place name is Old English ea "river" (see ea) + tun "farm, settlement."
Etruscan (n.) Look up Etruscan at Dictionary.com
1706, from Latin Etruscus "an Etruscan," from Etruria, ancient name of Tuscany, of uncertain origin, but containing an element that might mean "water" (see Basque) and which could be a reference to the rivers in the region.
Etta Look up Etta at Dictionary.com
fem. proper name, originally a shortening of Henrietta.
ettin (n.) Look up ettin at Dictionary.com
an old word for "a giant," extinct since 16c., from Old English eoten "giant, monster," from Proto-Germanic *itunoz "giant" (cognates: Old Norse iotunn, Danish jætte).