Online Etymology Dictionary

etymologist (n.): 1630s; see etymology + -ist. Also etymologer (1640s).
etymologize (v.): 1530s (transitive); see etymology + -ize. Compare French étymologiser, from Medieval Latin etymologisare. Intransitive sense from 1650s. Related: Etymologized; etymologizing.
etymology (n.): late 14c., ethimolegia "facts of the origin and development of a word," from Old French etimologie, ethimologie (14c., Modern French étymologie), from Latin etymologia, from Greek etymologia "analysis of a word to find its true origin," properly "study of the true sense (of a word)," with -logia "study of, a speaking of" (see -logy) + etymon "true sense," neuter of etymos "true, real, actual," related to eteos "true," which perhaps is cognate with Sanskrit satyah, Gothic sunjis, Old English soð "true."

Latinized by Cicero as veriloquium. In classical times, with reference to meanings; later, to histories. Classical etymologists, Christian and pagan, based their explanations on allegory and guesswork, lacking historical records as well as the scientific method to analyze them, and the discipline fell into disrepute that lasted a millennium. Flaubert ["Dictionary of Received Ideas"] wrote that the general view was that etymology was "the easiest thing in the world with the help of Latin and a little ingenuity."

As a modern branch of linguistic science treating of the origin and evolution of words, from 1640s. As "account of the particular history of a word" from mid-15c. Related: Etymological; etymologically.
etymon (n.): "primitive word," 1570s, from Greek etymon, neuter of etymos "true, real, actual" (see etymology). Classical Greek used etymon as an adverb, "truly, really." Related: Etymic.
eu-: word-forming element, in modern use meaning "good, well," from comb. form of Greek eus "good," eu "well" (adv.), also "luckily, happily" (opposed to kakos), as a noun, "the right, the good cause," from PIE *(e)su- "good" (source also of Sanskrit su- "good," Avestan hu- "good"). In compounds the Greek word had more a sense of "greatness, abundance, prosperity," and was opposed to dys-.
eubacteria (n.): singular eubacterium, 1939, coined in German 1930; see eu-, here meaning "good," + bacteria. Classically, as an adverb, eu should form compounds only with verbs.
Euboea: large island of Greece north of Attica and Boeotia, literally "rich in cattle," from eu- "good, well" (see eu-) + bous "ox, cow" (see cow (n.)). Related: Euboean.
eucalyptus (n.): evergreen genus of Australia, 1789, from Modern Latin, coined 1788 by French botanist Charles Louis L'héritier de Brutelle (1746-1800) from Greek eu "well" (see eu-) + kalyptos "covered" (see Calypso); so called for the covering on the bud.
Eucharist (n.): "sacrament of the Lord's Supper, the Communion," mid-14c., from Old French eucariste, from Late Latin eucharistia, from Greek eukharistia "thanksgiving, gratitude," later "the Lord's Supper," from eukharistos "grateful," from eu "well" (see eu-) + stem of kharizesthai "show favor," from kharis "favor, grace," from PIE root *gher- (5) "to like, want" (see hortatory). Eukharisteo is the usual verb for "to thank, to be thankful" in the Septuagint and Greek New Testament. Related: Eucharistic.
euchre (n.): type of card game played with a partial deck, 1846, American English, of unknown origin. Elements of the game indicate it might be from GermanIn early use also uker, yucker.
Euclidean (adj.): 1650s, "of or pertaining to Euclid" (Greek Eukleides), c. 300 B.C.E. geometer of Alexandria. Now often used in contrast to alternative models based on rejection of some of his axioms. His name in Greek means "renowned, glorious," from eu "well" (see eu-) + kleos "fame" (see Clio).
eudaemonic (adj.): also eudemonic, "producing happiness," 1856, from Greek eudaimonikos "conducive to happiness," from eudaimonia "happiness," from eu "good" (see eu-) + daimon "guardian, genius" (see daimon). Related: Eudaimonia; eudemonia; eudaemonical.
Eudora: fem. proper name, Greek, literally "generous," fem. of eudoros, from eu "well, good" (see eu-) + doron "gift" (see date (n.1)).
Eugene: masc. proper name, from French Eugène, from Latin Eugenius, from Greek Eugenios, literally "nobility of birth," from eugenes "well-born" (see eugenics).
Eugenia: fem. proper name, from Latin, from Greek Eugenia, literally "nobility of birth," fem. of Eugenius (see Eugene).
eugenics (n.): "doctrine of progress in evolution of the human race, race-culture," 1883, coined (along with adjective eugenic) by English scientist Francis Galton (1822-1911) on analogy of ethics, physics, etc. from Greek eugenes "well-born, of good stock, of noble race," from eu- "good" (see eu-) + genos "birth" (see genus).
The investigation of human eugenics, that is, of the conditions under which men of a high type are produced. [Galton, "Human Faculty," 1883]
euhemerism (n.): 1846, "the method of regarding myths as glorified accounts of actual events or persons," with -ism + name of Euhemerus, Greek philosopher of Sicily (4c. B.C.E.), who wrote "Iera Anagraphe," in which he maintained the Greek deities actually were historical mortals. His name is literally "good day," from eu "well, good" (see eu-) + hemera "day" (see ephemera). Related: Euhemerist; euhemeristic.
eukaryotic (adj.): also eucaryotic, "characterized by well-defined cells (with nuclei and cell walls)," 1957, from French eucaryote (1925), from Greek eu "well, good" (see eu-) + karyon "nut, kernel" (see karyo-). Related: Eukaryote; eucaryote.
eulogist (n.): 1758; see eulogy + -ist. Related: Eulogistic.
eulogize (v.): 1753, from eulogy + -ize. Related: Eulogized; eulogizing.
eulogy (n.): mid-15c., from Latin eulogium, from Greek eulogia "praise; good or fine language" (in New Testament, "blessing"), from eu "well" (see eu-) + -logia "speaking" (see -logy). Eu legein meant "speak well of."
Eumenides: Greek, literally "the well-minded ones," a euphemism of the Erinys; see eu- "well, good;" second element from Greek menos "spirit, passion," from PIE *men-es-, suffixed form of *men- (1) "to think" (see mind (n.)).
Eunice: fem. proper name, from Latinized form of Greek Eunike, literally "victorious," from eu "good, well" (see eu-) + nike "victory" (see Nike).
eunuch (n.): "castrated man," late 14c., from Middle French eunuque and directly from Latin eunuchus, from Greek eunoukhos "castrated man," originally "guard of the bedchamber or harem," from euno-, comb. form of eune "bed," a word of unknown origin, + -okhos, from stem of ekhein "to have, hold" (see scheme (n.)).
Eunuches is he þat is i-gilded, and suche were somtyme i-made wardeynes of ladyes in Egipt. [John of Trevisa, translation of Higdon's Polychronicon, 1387]
Harem attendants in Oriental courts and under the Roman emperors were charged with important affairs of state. The Greek and Latin forms of the word were used in the sense "castrated man" in the Bible but also to translate Hebrew saris, which sometimes meant merely "palace official," in Septuagint and Vulgate, probably without an intended comment on the qualities of bureaucrats. Related: Eunuchal; eunuchry; eunuchize.
eupeptic (adj.): 1831, from Greek eupeptos "having good digestion," from eu- "well, good" (see eu-) + peptos "digested" (see peptic).
euphemism (n.): 1650s, from Greek euphemismos "use of a favorable word in place of an inauspicious one," from euphemizein "speak with fair words, use words of good omen," from eu- "good, well" (see eu-) + pheme "speech, voice, utterance, a speaking," from phanai "speak" (see fame (n.)).

In ancient Greece, the superstitious avoidance of words of ill-omen during religious ceremonies, or substitutions such as Eumenides "the Gracious Ones" for the Furies (see also Euxine). In English, a rhetorical term at first; broader sense of "choosing a less distasteful word or phrase than the one meant" is first attested 1793. Related: Euphemistic; euphemistically.
euphemistic (adj.): 1830; see euphemism + -istic. Related: Euphemistically (1833).
euphony (n.): mid-15c., from Middle French euphonie, from Late Latin euphonia, from Greek euphonia "sweetness of voice," related to euphonos "well-sounding," from eu- "good" (see eu-) + phone "sound, voice," from PIE root *bha- (2) "to speak, tell, say" (see fame (n.)). Related: Euphonic (1782); euphonical (1660s); euphonious (1774). Hence, also, euphonium (1864), the musical instrument.
euphoria (n.): 1727, a physician's term for "condition of feeling healthy and comfortable (especially when sick)," medical Latin, from Greek euphoria "power of enduring easily," from euphoros, literally "bearing well," from eu "well" (see eu-) + pherein "to carry" (see infer). Non-technical use, now the main one, dates to 1882 and perhaps is a reintroduction. Earlier the word meant "effective operation of a medicine on a patient" (1680s).
euphoric (adj.): "characterized by euphoria," 1885, originally with reference to cocaine, from euphoria + -ic. The noun meaning "a drug which causes euphoria" also is from 1885. Euphoriant is from 1946 as a noun, 1947 as an adjective.
Euphrates: Mesopotamian river, arising in Armenia and flowing to the Persian Gulf, Old English Eufrate, from Greek Euphrates, from Old Persian Ufratu, perhaps from Avestan huperethuua "good to cross over," from hu- "good" + peretu- "ford." But Kent says "probably a popular etymologizing in O.P. of a local non-Iranian name" ["Old Persian," p.176]. In Akkadian, purattu. Related: Euphratean.
Euphrosyne: name of one of the three Graces in Greek mythology, via Latin, from Greek Euphrosyne, literally "mirth, merriment," from euphron "cheerful, merry, of a good mind," from eu "well, good" (see eu-) + phren (genitive phrenos) "mind," which is of unknown origin.
Euphues: chief character in two popular books by English writer John Lyly (1553-1606), from Greek euphyes "well-endowed by nature." The affected and ornate style of writing and speech popularized by the works was fashionable late 16c.-early 17c.; hence euphuism (1590s); euphuistic; euphuist.
Eurafrican (adj.): 1884 of the region of the Atlantic beside both continents; ; see Euro- + African Transferred or re-coined to describe the "colored" population of South Africa (1920s) and political situations involving both continents (1909).
Eurasia (n.): 1881, from Euro- + Asia. First record of it in any language seems to be in H. Reusche's "Handbuch der Geographie" (1858), but see Eurasian. Related: Eurasiatic (1863).
Eurasian (adj.): 1844, from Euro- + Asian. Originally of children of British-East Indian marriages; meaning "of Europe and Asia considered as one continent" is from 1868. As a noun from 1845.
eureka: c. 1600, from Greek heureka "I have found (it)," first person singular perfect active indicative of heuriskein "to find" (see heuristic). Supposedly shouted by Archimedes (c. 287-212 B.C.E.) when he solved a problem that had been set to him: determining whether goldsmiths had adulterated the metal in the crown of Hiero II, king of Syracuse.
Euripus: strait between Euboea and the Greek mainland, notorious for its violent and unpredictable currents, from eu- "good, well" (see eu-) + rhipe "rush." Apparently euphemistic.
Euro (n.): name for the basic monetary unit of a pan-European currency, from 1996.
Euro-: before vowels Eur-, word forming element meaning "Europe, European," from comb. form of Europe.
Eurocentric (adj.): 1963, from Euro- + -centric.
Europe: from Latin Europa "Europe," from Greek Europe, which is of uncertain origin; as a geographic name first recorded in the Homeric hymn to Apollo (522 B.C.E. or earlier):
"Telphusa, here I am minded to make a glorious temple, an oracle for men, and hither they will always bring perfect hecatombs, both those who live in rich Peloponnesus and those of Europe and all the wave-washed isles, coming to seek oracles."
Often explained as "broad face," from eurys "wide" (see eury-) + ops "face," literally "eye" (see eye (n.)). But also traditionally linked with Europa, Phoenician princess in Greek mythology. Klein (citing Heinrich Lewy) suggests a possible Semitic origin in Akkad. erebu "to go down, set" (in reference to the sun) which would parallel orient. Another suggestion along those lines is Phoenician 'ereb "evening," hence "west."
European: c. 1600 (adj.); 1630s (n.), from French Européen, from Latin Europaeus, from Greek Europaios "European," from Europe (see Europe).
europium (n.): rare earth element, 1901, named by its discoverer, French chemist Eugène Demarçay (1852-1903) in 1896, from Europe. With metallic element ending -ium.
eury-: word-forming element meaning "wide," from comb. form of Greek eurys "broad, wide," from PIE root *were- (1) "wide, broad" (source also of Sanskrit uruh "broad, wide").
Eurydice: wife of Orpheus in Greek mythology, from Latinized form of Greek Eurydike, literally "wide justice," from eurys "wide" (see eury-) + dike "custom, usage; justice, right; court case," from PIE *dika-, from root *deik- (see diction).
eurypterid (n.): fossil swimming crustacean of the Silurian and Devonian, 1874, from Greek eurys "broad, wide" (see eury-) + pteron "feather, wing" (see ptero-); so called from their swimming appendages.
eurythmic (adj.): also eurhythmic, "harmonious," 1831, from Greek eurythmia "rhythmical order," from eurythmos "rhythmical, well-proportioned," from eu "well, good" (see eu-) + rhythmos "measured flow or movement, rhythm; proportion, symmetry" (see rhythm). Related: Eurythmics (1912 in reference to a system of rhythmical bodily movements or dance exercises); eurythmy.
Eustace: masc. proper name, from Old French Eustace (Modern French Eustache), from Latin Eustachius, probably from Greek eustakhos "fruitful," from eu "well, good" (see eu-) + stakhys "ear (of grain);" see spike (n.1).
Eustachian tube (n.): so called for Italian physician Bartolomeo Eustachio (d.1574), who discovered the passages from the ears to the throat. His name is from Latin Eustachius (see Eustace).