Online Etymology Dictionary

epicenter (n.): 1887, from Modern Latin epicentrum (1879 in geological use); see epi- + center. Related: Epicentral (1866).
epicentre (n.): chiefly British English spelling of epicenter; for spelling, see -re.
epicure (n.): late 14c., "follower of Epicurus," from Latin Epicurus, from Greek Epicouros (341-270 B.C.E.), Athenian philosopher who taught that pleasure is the highest good and identified virtue as the greatest pleasure; the first lesson recalled, the second forgotten, and the name used pejoratively for "one who gives himself up to sensual pleasure" (1560s), especially "glutton, sybarite" (1774). Epicurus' school opposed by stoics, who first gave his name a reproachful sense. Non-pejorative meaning "one who cultivates refined taste in food and drink" is from 1580s.
epicurean (n.): late 14c., "follower of the philosophical system of Epicurus;" 1570s, "one devoted to pleasure," from Old French Epicurien, or from epicure + -ian. As an adjective, attested from 1580s in the philosophical sense and 1640s with the meaning "pleasure-loving."
epicureanism (n.): 1751, with reference to a philosophy; 1847 in a general sense, from epicurean + -ism. Earlier was epicurism (1570s).
epicureous (adj.): "epicurean," 1550s, from Latin epicureus, from Greek epikoureios (see epicure).
epicycle (n.): late 14c., from Latin epicyclus, from Greek epikyklos, from epi (see epi-) + kyklos (see cycle (n.)).
epidemic (adj.): c.1600, from French épidémique, from épidemié "an epidemic disease," from Medieval Latin epidemia, from Greek epidemia "prevalence of an epidemic disease" (especially the plague), from epi "among, upon" (see epi-) + demos "people, district" (see demotic).
epidemic (n.): 1757, from epidemic (adj.); earlier epideme (see epidemy). An Old English noun for this (persisting in Middle English) was man-cwealm.
epidemiology (n.): "study of epidemics," 1873, from Greek epidemios "epidemic" (see epidemic) + -logy. Related: Epidemiological; epidemiologist.
epidemy (n.): "an epidemic disease," especially the plague, late 15c., ipedemye, impedyme, from Old French ypidime (12c., Modern French épidémie), from Late Latin epidemia (see epidemic (adj.)).
epidermis (n.): 1620s, from Greek epidermis, from epi "on" (see epi-) + derma "skin" (see derma). Related: Epidermal; epidermic.
epididymis (n.): c.1600, "fleshy mass at the back of the testicles," Modern Latin, literally "that which is on the testicles," from Greek epididymis, a word probably coined by Greek anatomist Herophilus (c.300 B.C.E.) from epi "on" (see epi-) + didymos "testicle," literally "double, twofold" (adj.). "To save his Epididamies" [Richard Brome, "The Court Beggar," 1652].
epidural (adj.): 1882, from epi- + dura (mater) (see dura mater). The noun meaning “injection into the epidural region” (usually during childbirth) is attested by 1970.
epiglottis (n.): 1520s, from Late Latin epiglottis, from Greek epiglottis, literally "(that which is) upon the tongue," from epi "on" (see epi-) + glottis, from glotta, variant of glossa "tongue" (see gloss (n.2)). An earlier form was epiglote (c.1400), from Old French epiglotte. Related: Epiglottic.
epigone (n.): also epigon, "undistinguished scions of mighty ancestors," (sometimes in Latin plural form epigoni), from Greek epigonoi, in classical use with reference to the sons of the Seven who warred against Thebes; plural of epigonos "born afterward" from epi (see epi-) + -gonos, from root of gignesthai "to be born" related to genos "race, birth, descent" (see genus).
epigram (n.): mid-15c., from Middle French épigramme, from Latin epigramma "an inscription," from Greek epigramma "an inscription, epitaph, epigram," from epigraphein "to write on, inscribe" (see epigraph). Related: Epigrammatist.
epigrammatic (adj.): 1704, shortened from epigrammatical (c.1600); see epigram.
epigraph (n.): 1620s, "inscription on a building, statue, etc.," from Greek epigraphe "an inscription," from epigraphein "to write on," from epi "on" (see epi-) + graphein "to write" (see -graphy). Sense of "motto; short, pithy sentence at the head of a book or chapter" first recorded in English 1844.
epilepsy (n.): 1570s, from Middle French epilepsie (16c.), from Late Latin epilepsia, from Greek epilepsia "seizure," from epi "upon" (see epi-) + lepsis "seizure," from leps-, future stem of lambanein "take hold of, grasp" (see analemma).

Earlier was epilencie (late 14c.), from Middle French epilence, with form influenced by pestilence. The native name was falling sickness.
epileptic (adj.): c.1600, from French épileptique, from Late Latin epilepticus, from Greek epileptikos, from epilambanein (see epilepsy). Earlier adjective was epilentic (late 14c.), from a Greek variant. As a noun from 1650s.
epilogue (n.): early 15c., from Middle French epilogue (13c.), from Latin epilogus, from Greek epilogos "conclusion of a speech," from epi "upon, in addition" (see epi-) + logos "a speaking" (see lecture (n.)). Earliest English sense was theatrical.
epinephrine (n.): 1883, from epi- "upon" + Greek nephros "kidney" (see nephron) + chemical suffix -ine (2). So called because the adrenal glands are on the kidneys.
epiphany (n.): early 14c., "festival of the manifestation of Christ to the gentiles" (celebrated Jan. 6; usually with a capital -E-), from Old French epiphanie, from Late Latin epiphania, neuter plural (taken as feminine singular), from late Greek epiphaneia "manifestation, striking appearance" (in New Testament, "advent or manifestation of Christ"), from epiphanes "manifest, conspicuous," from epiphainein "to manifest, display," from epi "on, to" (see epi-) + phainein "to show" (see phantasm).

Of divine beings other than Christ, first recorded 1660s; general literary sense of "any manifestation or revelation" appeared 1840, first in De Quincey.
epiphenomenon (n.): 1706, "secondary symptom," from epi- + phenomenon. Plural is epiphenomena. Related: Epiphenomenal.
epiphyte (n.): 1816 (implied in epiphytous), from epi- "upon" + -phyte "plant."
episcopacy (n.): 1640s; see episcopal + -cy.
episcopal (adj.): mid-15c., from Middle French épiscopal (14c.), from Late Latin episcopalis, from Latin episcopus "an overseer" (see bishop). Reference to a church governed by bishops is 1752. With a capital E-, the ordinary designation of the Anglican church in the U.S. and Scotland.
episcopalian: 1738 (n.), 1768 (adj.), from episcopal + -ian. Related: Episcopalianism.
episiotomy (n.): 1878, from comb. form of Greek epision "the pubic region" + -tomy "a cutting."
episode (n.): 1670s, "commentary between two choric songs in a Greek tragedy," also "an incidental narrative or digression within a story, poem, etc.," from French épisode or directly from Greek epeisodion "addition," noun use of neuter of epeisodios "coming in besides," from epi "in addition" (see epi-) + eisodos "a coming in, entrance" (from eis "into" + hodos "way"). Sense of "outstanding incident, experience" first recorded in English 1773. Transferred by 1930s to individual broadcasts of serial radio programs.
episodic (adj.): 1711, from episode + -ic. Episodical is from 1660s.
epistasis (n.): medical Latin, from Greek epistasis "a stopping, stoppage," from epi "upon" (see epi-) + stasis "a stopping or standing" (see stasis).
epistaxis (n.): medical Latin, from Greek epistaxis "nosebleeding," from epi "upon" (see epi-) + stazein- "to let fall in drops" (see stalactite).
epistemic (adj.): 1922, from Greek episteme "knowledge" (see epistemology) + -ic.
epistemology (n.): "theory of knowledge," 1856, coined by Scottish philosopher James F. Ferrier (1808-1864) from Greek episteme "knowledge," from Ionic Greek epistasthai "know how to do, understand," literally "overstand," from epi "over, near" (see epi-) + histasthai "to stand," (see histo-).

The scientific (as opposed to philosophical) study of the roots and paths of knowledge is epistemics (1969). Related: Epistemological; epistemologically.
epistle (n.): Old English epistol, from Old French epistle, epistre (Modern French épitre), from Latin epistola "letter," from Greek epistole "message, letter, command, commission," whether verbal or in writing, from epistellein "send to," from epi "to" (see epi-) + stellein in its secondary sense of "to dispatch, send" from PIE *stel-yo-, suffixed form of root *stel- "to put, stand," with derivatives referring to a standing object or place (see stall (n.1)).

Also acquired in Old English directly from Latin as pistol. Specific sense of "letter from an apostle forming part of canonical scripture" is c.1200.
epistolary (adj.): 1650s, from French épistolaire, from Latin epistolaris, from epistola (see epistle).
epistrophe (n.): 1640s, from Late Latin epistrophe, from Greek epistrophe "a turning about," from epi "upon" (see epi-) + strophe "a turning" (see strophe).
epitaph (n.): mid-14c., from Old French epitaphe (12c.) and directly from Medieval Latin epitaphium "funeral oration, eulogy," from Greek epitaphion "a funeral oration," noun use of neuter of epitaphos "of a funeral," from epi "at, over" (see epi-) + taphos "tomb, funeral rites," from PIE root *dhembh- "to bury." Among the Old English equivalents was byrgelsleoð.
epithalamium (n.): 1590s, "bridal song," from Latin epithalamium, from Greek epithalamion "a bridal song," from epi "at, upon" (see epi-) + thalamos "bridal chamber, inner chamber."
epithelium (n.): 1748, Modern Latin (Frederick Ruysch), from Greek epi "upon" (see epi-) + thele "teat, nipple" (see fecund). Related: Epithelial.
epithet (n.): 1570s, "descriptive name for a person or thing," from Middle French épithète or directly from Latin epitheton, from Greek epitheton "something added," adjective often used as noun, from neuter of epithetos "attributed, added," from epitithenai "to add on," from epi "in addition" (see epi-) + tithenai "to put" (see factitious).
epitome (n.): 1520s, "an abstract; brief statement of the chief points of some writing," from Middle French épitomé (16c.), from Latin epitome "abridgment," from Greek epitome "abridgment," from epitemnein "cut short, abridge," from epi "into" (see epi-) + temnein "to cut" (see tome). Sense of "person or thing that typifies something" is first recorded c.1600.
epitomise (v.): chiefly British English spelling of epitomize. For spelling, see -ize. Related: Epitomising; epitomises.
epitomize (v.): 1590s, "shorten, condense," from epitome + -ize. Meaning "typify, embody" is from 1620s. Related: Epitomized; epitomizing; epitomizes.
epizootic (n.): animal equivalent of epidemic, 1748, from French épizootique, from épizootie, irregularly formed from Greek epi (see epi-) + zoon (see zoo).
epoch (n.): 1610s, epocha, "point marking the start of a new period in time" (e.g. the founding of Rome, the birth of Christ, the Hegira), from Late Latin epocha, from Greek epokhe "stoppage, fixed point of time," from epekhein "to pause, take up a position," from epi "on" (see epi-) + ekhein "to hold" (see scheme (n.)). Transferred sense of "a period of time" is 1620s; geological usage (not a precise measurement) is from 1802.
epochal (adj.): 1680s, from epoch + -al (1).
epode (n.): 1590s, a kind of lyric poem in which a short line follows a longer one (invented by Archilochus, also used by Horace), from Latin epodos, from Greek epodus "after-song, incantation," from epi "after" (see epi-) + odein "to sing" (see ode).