exoteric (adj.) Look up exoteric at Dictionary.com
1650s, from Late Latin exotericus, from Greek exoterikos "external, belonging to the outside," from exotero, comparative of exo (see exo-).
exothermic (adj.) Look up exothermic at Dictionary.com
"relating to a liberation of heat," 1879, modeled on French exothermique (1879); see exo- + thermal.
exotic (adj.) Look up exotic at Dictionary.com
1590s, "belonging to another country," from Middle French exotique (16c.) and directly from Latin exoticus, from Greek exotikos "foreign," literally "from the outside," from exo "outside" (see exo-). Sense of "unusual, strange" in English first recorded 1620s, from notion of "alien, outlandish." In reference to strip-teasers and dancing girls, it is attested by 1942, American English.
Exotic dancer in the nightclub trade means a girl who goes through a few motions while wearing as few clothes as the cops will allow in the city where she is working ... ["Life," May 5, 1947]
As a noun from 1640s, "anything of foreign origin," originally plants.
exoticism (n.) Look up exoticism at Dictionary.com
1827, from exotic + -ism.
expand (v) Look up expand at Dictionary.com
early 15c., "spread out, open out, spread flat, extend widely;" also transitive, "cause to grow larger;" from Anglo-French espaundre, Old French espandre "spread, spread out, be spilled," and directly from Latin expandere "to spread out, unfold, expand," from ex- "out" (see ex-) + pandere "to spread, stretch" (see pace (n.)). Related: Expanded; expanding.
expanse (n.) Look up expanse at Dictionary.com
1660s, from Latin expansum, noun use of neuter of expansus, past participle of expandere "to spread out" (see expand).
expansion (n.) Look up expansion at Dictionary.com
1610s, "anything spread out;" 1640s, "act of expanding," from French expansion, from Late Latin expansionem (nominative expansio) "a spreading out," noun of action from past participle stem of Latin expandere "to spread out" (see expand).
expansionist (n.) Look up expansionist at Dictionary.com
1874, American English, in reference to money policy; by 1884 as "one who advocates the expansion of the territory of his nation," from expansion + -ist. Related: Expansionism.
expansive (adj.) Look up expansive at Dictionary.com
1650s, "tending to expand," from Latin expans-, past participle stem of expandere "to spread out" (see expand) + -ive. Meaning "embracing a large number of particulars, comprehensive" is by 1813. Related: Expansively; expansiveness.
expat (n.) Look up expat at Dictionary.com
1962, shortening of expatriate (n.).
expatiate (v.) Look up expatiate at Dictionary.com
1530s, "walk about, roam freely," from Latin expatiatus/exspatiatus, past participle of expatiari/exspatiari "wander, digress, wander from the way; spread, extend," from ex- "out" (see ex-) + spatiari "to walk, spread out," from spatium (see space (n.)). Meaning "talk or write at length" is 1610s. Related: Expatiated; expatiating.
expatiation (n.) Look up expatiation at Dictionary.com
1610s, noun of action from expatiate.
expatriate (v.) Look up expatriate at Dictionary.com
1768, modeled on French expatrier "banish" (14c.), from ex- "out of" (see ex-) + patrie "native land," from Latin patria "one's native country," from pater (genitive patris) "father" (see father (n.); also compare patriot). Related: Expatriated; expatriating. The noun is by 1818, "one who has been banished;" main modern sense of "one who chooses to live abroad" is by 1902.
expatriation (n.) Look up expatriation at Dictionary.com
1767, from French expatriation, noun of action from expatrier (see expatriate).
expect (v.) Look up expect at Dictionary.com
1550s, "wait, defer action," from Latin expectare/exspectare "await, look out for; desire, hope, long for, anticipate; look for with anticipation," from ex- "thoroughly" (see ex-) + spectare "to look," frequentative of specere "to look at" (see scope (n.1)).

Figurative sense of "anticipate, look forward to" developed in Latin and is attested in English from c. 1600. Also from c. 1600 as "regard as about to happen." Meaning "count upon (to do something), trust or rely on" is from 1630s. Used since 1817 as a euphemism for "be pregnant." In the sense "suppose, reckon, suspect," it is attested from 1640s but was regarded as a New England provincialism. Related: Expected; expecting.
expectancy (n.) Look up expectancy at Dictionary.com
1590s, from Medieval Latin expectantia, from Latin expectans (see expectant) + -ancy. Related: Expectance.
expectant (adj.) Look up expectant at Dictionary.com
late 14c., from Old French expectant or directly from Latin expectantem/exspectantem (nominative expectans/exspectans), present participle of expectare/exspectare "await, desire, hope" (see expect). Meaning "pregnant" is by 1861. Related: Expectantly. As a noun, "one who waits in expectation," from 1620s.
expectation (n.) Look up expectation at Dictionary.com
1530s, from Middle French expectation (14c.) or directly from Latin expectationem/exspectationem (nominative expectatio/exspectatio) "anticipation, an awaiting," noun of action from past participle stem of expectare/exspectare (see expect). Related: Expectations.
expectorant (n.) Look up expectorant at Dictionary.com
in medicine, 1782, from Latin expectorantem (nominative expectorans), present participle of expectorare (see expectorate). From 1811 as an adjective.
expectorate (v.) Look up expectorate at Dictionary.com
c. 1600, "to clear out the chest or lungs," a literal use of Latin expectoratus, past participle of expectorare, which in classical use was figurative, "scorn, expel from the mind," literally "drive from the breast, make a clean breast," from ex- "out" (see ex-) + pectus (genitive pectoris) "breast" (see pectoral (adj.)). Its use as a euphemism for "spit" is recorded by 1827. The classical Latin figurative sense appears in English 17c. but is now obsolete. Related: Expectorated; expectorating.
expectoration (n.) Look up expectoration at Dictionary.com
1670s, noun of action from expectorate.
expediate (v.) Look up expediate at Dictionary.com
a 17c. error for expedite that has gotten into the dictionaries.
expedience (n.) Look up expedience at Dictionary.com
mid-15c., "advantage, benefit," from Old French expedience, from Late Latin expedientia, from expedientem (see expedient). From "that which is expedient," the sense tends toward "utilitarian wisdom." Meaning "quality of being expedient" is from 1610s. Related: Expediency (1610s).
expedient (adj.) Look up expedient at Dictionary.com
late 14c., "advantageous, fit, proper to a purpose," from Old French expedient "useful, beneficial" (14c.) or directly from Latin expedientem (nominative expediens) "beneficial," present participle of expedire "make fit or ready, prepare" (see expedite). The noun meaning "a device adopted in an exigency, that which serves to advance a desired result" is from 1650s. Related: Expediential; expedientially (both 19c.).
Expedient, contrivance, and device indicate artificial means of escape from difficulty or embarrassment; resource indicates natural means or something possessed; resort and shift may indicate either. [Century Dictionary]
expediently (adv.) Look up expediently at Dictionary.com
late 14c., from expedient (adj.) + -ly (2).
expedite (v.) Look up expedite at Dictionary.com
c. 1500 (implied in past participle expedit "accomplished"), from Latin expeditus, past participle of expedire "extricate, disengage, liberate; procure, make ready, put in order, make fit, prepare; explain, make clear," literally "free the feet from fetters," hence to liberate from difficulties, from ex- "out" (see ex-) + *pedis "fetter, chain for the feet," related to pes (genitive pedis) "foot," from PIE root *ped- (1) "a foot" (see foot (n.)). Compare Greek pede "fetter." Related: Expedited; expediting.
expedition (n.) Look up expedition at Dictionary.com
early 15c., "military campaign; the act of rapidly setting forth," from Old French expedicion "an expediting, implementation; expedition, mission" (13c.) and directly from Latin expeditionem (nominative expeditio) "an enterprise against an enemy, a military campaign," noun of action from past participle stem of expedire "make ready, prepare" (see expedite). Meaning "journey for some purpose" is from 1590s. Sense by 1690s also included the body of persons on such a journey.
expeditionary (adj.) Look up expeditionary at Dictionary.com
1803, from expedition + -ary.
expeditious (adj.) Look up expeditious at Dictionary.com
late 15c., expedycius "useful, fitting," from Latin expeditus "disengaged, ready, convenient, prompt; unfettered, unencumbered," past participle of expedire (see expedite). Meaning "speedy, speedily accomplished" is from 1590s. Related: Expeditiously; expeditiousness.
expel (v.) Look up expel at Dictionary.com
late 14c., "cast out," from Latin expellere "drive out, drive away," from ex- "out" (see ex-) + pellere "to drive" (see pulse (n.1)). Specific meaning "to eject from a school" is first recorded 1640s. Related: Expelled; expelling.
expellee (n.) Look up expellee at Dictionary.com
1888, from expel + -ee.
expend (v.) Look up expend at Dictionary.com
early 15c., from Latin expendere "pay out, weigh out money," from ex- "out" (see ex-) + pendere "to pay, weigh" (see pendant). Related: Expended; expending.
expendable (adj.) Look up expendable at Dictionary.com
1805, from expend + -able.
expenditure (n.) Look up expenditure at Dictionary.com
1769, "act of expending," from Medieval Latin expenditus, irregular past participle of Latin expendere "to weigh out; to pay out" (see expend) + -ure. Meaning "that which is expended" is from 1791. Related: Expenditures.
expense (n.) Look up expense at Dictionary.com
also formerly expence, late 14c., "action of spending or giving away, a laying out or expending," also "funds provided for expenses, expense money; damage or loss from any cause," from Anglo-French expense, Old French espense "money provided for expenses," from Late Latin expensa "disbursement, outlay, expense," noun use of neuter plural past participle of Latin expendere "to weigh out money, to pay down" (see expend).

Latin spensa also yielded Medieval Latin spe(n)sa, the sense of which specialized to "outlay for provisions," then "provisions, food" before it was borrowed into Old High German as spisa and became the root of German Speise "food," now mostly meaning prepared food, and speisen "to eat." Expense account is from 1872.
expense (v.) Look up expense at Dictionary.com
1909, from expense (n.). Related: Expensed; expensing.
expenses (n.) Look up expenses at Dictionary.com
"charges incurred in the discharge of duty," late 14c. See expense (n.).
expensive (adj.) Look up expensive at Dictionary.com
1620s, "given to profuse expenditure," from expense (n.) + -ive. Meaning "costly, requiring profuse expenditure" is from 1630s. Earlier was expenseful (c. 1600). Expenseless was in use mid-17c.-18c., but there seems now nothing notable to which it applies, and the dictionaries label it "obsolete." Related: Expensively; expensiveness.
experience (v.) Look up experience at Dictionary.com
1530s, "to test, try, learn by practical trial or proof;" see experience (n.). Sense of "feel, undergo" first recorded 1580s. Related: Experienced; experiences; experiencing.
experience (n.) Look up experience at Dictionary.com
late 14c., "observation as the source of knowledge; actual observation; an event which has affected one," from Old French esperience "experiment, proof, experience" (13c.), from Latin experientia "a trial, proof, experiment; knowledge gained by repeated trials," from experientem (nominative experiens) "experienced, enterprising, active, industrious," present participle of experiri "to try, test," from ex- "out of" (see ex-) + peritus "experienced, tested," from PIE root *per- (3) "to lead, pass over" (see peril). Meaning "state of having done something and gotten handy at it" is from late 15c.
experienced (adj.) Look up experienced at Dictionary.com
"having experience, taught by practice, skillful through doing," 1570s, past participle adjective from experience (v.).
experiential (adj.) Look up experiential at Dictionary.com
1640s (implied in experientially), from Latin experientia "knowledge gained by testing or trials" (see experience (n.)) + -al (1).
experiment (n.) Look up experiment at Dictionary.com
mid-14c., "action of observing or testing; an observation, test, or trial;" also "piece of evidence or empirical proof; feat of magic or sorcery," from Old French esperment "practical knowledge, cunning; enchantment, magic spell; trial, proof, example; lesson, sign, indication," from Latin experimentum "a trial, test, proof, experiment," noun of action from experiri "to test, try" (see experience (n.)).
experiment (v.) Look up experiment at Dictionary.com
late 15c., from experiment (n.). Intransitive sense by 1787. Related: Experimented; experimenting.
experimental (adj.) Look up experimental at Dictionary.com
mid 15c., "having experience," from experiment (n.) + -al (1). Meaning "based on experiment" is from 1560s. Meaning "for the sake of experiment" is from 1792.
experimentation (n.) Look up experimentation at Dictionary.com
1670s, noun of action from experiment (v.).
expert (adj.) Look up expert at Dictionary.com
late 14c., "having had experience; skillful," from Old French expert, espert "experienced, practiced, skilled" and directly from Latin expertus (contracted from *experitus), "tried, proved, known by experience," past participle of experiri "to try, test" (see experience). The adjective tends to be accented on the second syllable, the noun on the first. Related: Expertly; expertness.
expert (n.) Look up expert at Dictionary.com
early 15c., "person wise through experience," from expert (adj.). The word reappeared 1825 in the legal sense, "person who, by virtue of special acquired knowledge or experience on a subject, presumably not within the knowledge of men generally, may testify in a court of justice to matters of opinion thereon, as distinguished from ordinary witnesses, who can in general testify only to facts" [Century Dictionary].
expertise (n.) Look up expertise at Dictionary.com
"quality or state of being an expert," 1868, from French expertise (16c.) "expert appraisal, expert's report," from expert (see expert). Earlier and more English was expertness (c. 1600).
experto crede Look up experto crede at Dictionary.com
Latin, "take it from one who knows" ("Aeneid," xi.283); dative singular of expertus (see expert (adj.)) + imperative singular of credere (see credo).