ex cathedra Look up ex cathedra at Dictionary.com
Latin, literally "from the (teacher's) chair," from ex "out of" (see ex-) + cathedra (see cathedral).
ex libris Look up ex libris at Dictionary.com
Latin, literally "out of the books (of)," from ex "out of" (see ex-) + ablative plural of liber "book" (see library).
ex nihilo Look up ex nihilo at Dictionary.com
Latin, literally "out of nothing," from ex "out of" (see ex-) + nihilo, ablative of nihil "nothing" (see nil).
ex officio Look up ex officio at Dictionary.com
Latin, "in discharge of one's duties," literally "out of duty," from ex "out of" (see ex-) + officio, ablative of officium "duty" (see office).
ex parte Look up ex parte at Dictionary.com
Latin legal term, "on the one side only," from ex "out of" (see ex-) + parte, ablative of pars "part, side."
ex post facto Look up ex post facto at Dictionary.com
from Medieval Latin ex postfacto, "from what is done afterwards."
ex- Look up ex- at Dictionary.com
word-forming element, in English meaning mainly "out of, from," but also "upwards, completely, deprive of, without," and "former;" from Latin ex "out of, from within," from PIE *eghs "out" (cognates: Gaulish ex-, Old Irish ess-, Old Church Slavonic izu, Russian iz). In some cases also from Greek cognate ex, ek. PIE *eghs had comparative form *eks-tero and superlative *eks-t(e)r-emo-. Often assimilated to following consonant (elude, emerge, evaporate, etc.).
exacerbate (v.) Look up exacerbate at Dictionary.com
1650s, a back-formation from exacerbation or else from Latin exacerbatus, past participle of exacerbare. Related: Exacerbated; exacerbating.
exacerbation (n.) Look up exacerbation at Dictionary.com
c.1400, from Late Latin exacerbationem (nominative exacerbatio), noun of action from past participle stem Latin exacerbare "exasperate, irritate, provoke," from ex- "thoroughly" (see ex-) + acerbus "harsh, bitter," from acer "sharp, keen" (see acrid).
exact (adj.) Look up exact at Dictionary.com
"precise, rigorous, accurate," 1530s, from Latin exactus "precise, accurate, exact," past participle of exigere "demand, require," literally "to drive or force out," also "demand, finish, measure," from ex- "out" (see ex-) + agere "drive, lead, act" (see act (n.)).
exact (v.) Look up exact at Dictionary.com
mid-15c., from Latin exactus, past participle of exigere (see exact (adj.)). Older in English than the adjective and retaining the literal sense of the Latin source. Related: Exacted; exacting.
exacta (n.) Look up exacta at Dictionary.com
type of horse-racing bet, 1964, said to have originated in New York; from exact (adj.).
exacting (adj.) Look up exacting at Dictionary.com
"too demanding," 1580s, present participle adjective from exact (v.).
exaction (n.) Look up exaction at Dictionary.com
late 14c., from French exaction, from Latin exactionem (nominative exactio) "a driving out; supervision; exaction; a tax, tribute, impost," noun of action from past participle stem of exigere (see exact (adj.)).
exactitude (n.) Look up exactitude at Dictionary.com
1734, from French exactitude (17c.), from exact, from Latin exactus (see exact (adj.)).
exactly (adv.) Look up exactly at Dictionary.com
1530s, from exact (adj.) + -ly (2). Elliptical use for "quite right" not recorded before 1869.
exactness (n.) Look up exactness at Dictionary.com
1560s, "perfection," from exact (adj.) + -ness. Meaning "precision" is 1640s.
exaggerate (v.) Look up exaggerate at Dictionary.com
1530s, "to pile up, accumulate," from Latin exaggeratus, past participle of exaggerare "heighten, amplify, magnify," literally "to heap, pile, load, fill," from ex- "thoroughly" (see ex-) + aggerare "heap up," from agger (genitive aggeris) "heap," from aggerere "bring together, carry toward," from ad- "to, toward" (see ad-) + gerere "carry" (see gest). Sense of "overstate" first recorded in English 1560s. Related: Exaggerated; exaggerating.
exaggeration (n.) Look up exaggeration at Dictionary.com
1560s, from Latin exaggerationem (nominative exaggeratio), noun of action from past participle stem of exaggerare (see exaggerate).
exalt (v.) Look up exalt at Dictionary.com
late 14c., from Old French exalter (10c.), from Latin exaltare "raise, elevate," from ex- "out, up" (see ex-) + altus "high" (see old). Related: Exalted; exalting.
exaltation (n.) Look up exaltation at Dictionary.com
late 14c, from Old French exaltacion "enhancement, elevation," from Latin exaltationem (nominative exaltatio) "elevation, pride," from exaltare (see exalt).
exam (n.) Look up exam at Dictionary.com
shortened form of examination, 1848.
examination (n.) Look up examination at Dictionary.com
late 14c., "action of testing or judging; judicial inquiry," from Old French examinacion, from Latin examinationem (nominative examinatio), noun of action from past participle stem of examinare (see examine). Sense of "test of knowledge" is attested from 1610s.
examine (v.) Look up examine at Dictionary.com
c.1300, from Old French examiner "interrogate, question, torture," from Latin examinare "to test or try; weigh, consider, ponder," from examen "a means of weighing or testing," probably ultimately from exigere "weigh accurately" (see exact (adj.)). Related: Examined; examining.
examiner (n.) Look up examiner at Dictionary.com
early 14c., examinour, agent noun from examine.
example (n.) Look up example at Dictionary.com
late 14c., partial re-Latinization of earlier essample, asaumple (mid-13c.), from Old French essemple "sample, model, example, precedent, cautionary tale," from Latin exemplum "a sample," literally "that which is taken out," from eximere "take out, remove" (see exempt (adj.)). Oldest English senses are of "behavior" and "punishment."
exanimate (adj.) Look up exanimate at Dictionary.com
1530s, from Latin exanimatus "lifeless, dead," past participle of exanimare "to deprive of air or breath; tire, fatigue; to deprive of life; to terrify," from ex- (see ex-) + animare (see animate (v.)).
exarch (n.) Look up exarch at Dictionary.com
from Late Latin exarchus, from Greek exarkhos, from ex (see ex-) + arkhos "leader, chief, ruler" (see archon).
exasperate (v.) Look up exasperate at Dictionary.com
1530s, from Latin exasperatus, past participle of exasperare "roughen, irritate, provoke," from ex- "thoroughly" (see ex-) + asper "rough" (see asperity). Related: Exasperated; exasperating.
exasperation (n.) Look up exasperation at Dictionary.com
1540s, from Latin exasperationem (nominative exasperatio), noun of action from past participle stem of exasperare (see exasperate).
Excalibur (n.) Look up Excalibur at Dictionary.com
King Arthur's sword, c.1300, from Old French Escalibor, corruption of Caliburn, in Geoffrey of Monmouth (c.1140) Caliburnus, apparently from Welsh Caledvwlch probably a variant of the legendary Irish sword name Caladbolg which might mean literally "hard-belly," i.e. "voracious." For first element, see callus; for second, see belly (n.).
excavate (v.) Look up excavate at Dictionary.com
1590s, from Latin excavatus, past participle of excavare "to hollow out," from ex- "out" (see ex-) + cavare "to hollow, hollow out," from cavus "cave" (see cave (n.)). Related: Excavated; excavating.
excavation (n.) Look up excavation at Dictionary.com
1610s, "action of excavating," from Latin excavationem (nominative excavatio) "a hollowing out," noun of action from past participle stem of excavare (see excavate).
exceed (v.) Look up exceed at Dictionary.com
late 14c., from Old French exceder (14c.) "exceed, surpass, go too far," from Latin excedere "depart, go beyond, be in excess, surpass," from ex- "out" (see ex-) + cedere "go, yield" (see cede). Related: Exceeded; exceeding. Exceedingly (late 15c.) means "very greatly or very much;" excessively (mid-15c.) means "too greatly or too much."
excel (v.) Look up excel at Dictionary.com
c.1400, from Latin excellere "to rise, surpass, be eminent," from ex- "out from" (see ex-) + -cellere "rise high, tower," related to celsus "high, lofty, great," from PIE root *kel- "to rise, be elevated" (see hill). Related: Excelled; excelling.
excellence (n.) Look up excellence at Dictionary.com
mid-14c., from Old French excellence, from Latin excellentia, from excellentem (see excellent).
excellency (n.) Look up excellency at Dictionary.com
"high rank," c.1200, from Latin excellentia (see excellence); as a title of honor it dates from early 14c.
excellent (adj.) Look up excellent at Dictionary.com
mid-14c., from Old French excellent "outstanding, excellent," from Latin excellentem (nominative excellens), present participle of excellere (see excel). Related: Excellently.
excelsior Look up excelsior at Dictionary.com
Latin excelsior "higher," comparative of excelsus (adj.) "high, elevated, lofty," past participle of excellere (see excel). Taken 1778 as motto of New York State, where it apparently was mistaken for an adverb. Popularized 1841 as title of a poem by Longfellow. As a trade name for "thin shavings of soft wood used for stuffing cushions, etc.," first recorded 1868, American English.
except (v.) Look up except at Dictionary.com
late 14c., "to receive," from Middle French excepter (12c.), from Latin exceptus, past participle of excipere "take out," from ex- "out" (see ex-) + capere "to take" (see capable). Meaning "to leave out" is from 1510s. Related: Excepted; excepting. Adjectival function led to use as a preposition, conjunction (late 14c.).
exception (n.) Look up exception at Dictionary.com
late 14c., from Anglo-French excepcioun, Old French excepcion, from Latin exceptionem (nominative exceptio), noun of action from past participle stem of excipere (see except).

The exception that proves the rule is from law: exceptio probat regulam in casibus non exceptis, "the exception proves the rule in cases not excepted;" exception here being "action of excepting" someone or something from the rule in question, not the person or thing that is excepted. To take exception is from excipere being used in Roman law as a modern attorney would say objection.
exceptionable (adj.) Look up exceptionable at Dictionary.com
1660s, from exception + -able. Related: Exceptionably.
exceptional (adj.) Look up exceptional at Dictionary.com
1846, from exception + -al (1). Related: Exceptionally.
excerpt (v.) Look up excerpt at Dictionary.com
early 15c. (implied in excerpte), from Latin excerptus, past participle of excerpere "pluck out, pick out, extract, excerpt," from ex- "out" (see ex-) + carpere "pluck, gather," from PIE *kerp- "to gather, pluck, harvest" (see harvest (n.)). Related: Excerpted; excerpting.
excerpt (n.) Look up excerpt at Dictionary.com
1630s, from Latin excerptum "an extract, selection," noun use of neuter past participle of excerpere (see excerpt (v.)). Related: excerpts.
excess (n.) Look up excess at Dictionary.com
late 14c., from Old French exces (14c.) "excess, extravagance, outrage," from Latin excessus "departure, a going beyond the bounds of reason or beyond the subject," from stem of excedere "to depart, go beyond" (see exceed). As an adjective from late 15c.
excessive (adj.) Look up excessive at Dictionary.com
late 14c., from Old French excessif "excessive, oppressive," from Latin excess-, past participle stem of excedere "to depart, go beyond" (see exceed). Related: Excessively; excessiveness.
exchange (n.) Look up exchange at Dictionary.com
late 14c., "act of reciprocal giving and receiving," from Anglo-French eschaunge, Old French eschange (Modern French échange), from Late Latin excambium, from excambiare, from Latin ex- "out" (see ex-) + cambire "barter" (see change (v.)). Practice of merchants or lenders meeting to exchange bills of debt led to meaning "building for mercantile business" (1580s).
exchange (v.) Look up exchange at Dictionary.com
late 15c., from Old French eschangier "exchange, barter," from Vulgar Latin *excambiare (source of Italian scambiare); see exchange (n.). Related: Exchanged; exchanging.
exchequer (n.) Look up exchequer at Dictionary.com
c.1300, from Anglo-French escheker "a chessboard," from Old French eschequier, from Medieval Latin scaccarium "chess board" (see check (n.1); also see checker (n.2)). Government financial sense began under the Norman kings of England and refers to a cloth divided in squares that covered a table on which accounts of revenue were reckoned with counters, and which apparently reminded people of a chess board. Respelled with an -x- based on the mistaken belief that it originally was a Latin ex- word.