Online Etymology Dictionary

exoteric (adj.): 1650s, from Late Latin exotericus, from Greek exoterikos "external, belonging to the outside," from exotero, comparative of exo (see exo-).
exothermic (adj.): "relating to a liberation of heat," 1879, modeled on French exothermique (1879); see exo- + thermal.
exotic (adj.): 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.): 1827, from exotic + -ism.
expand (v): 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.): 1660s, from Latin expansum, noun use of neuter of expansus, past participle of expandere "to spread out" (see expand).
expansion (n.): 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.): 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.): 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.): 1962, shortening of expatriate (n.).
expatiate (v.): 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.): 1610s, noun of action from expatiate.
expatriate (v.): 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.): 1767, from French expatriation, noun of action from expatrier (see expatriate).
expect (v.): 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.): 1590s, from Medieval Latin expectantia, from Latin expectans (see expectant) + -ancy. Related: Expectance.
expectant (adj.): 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.): 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.): in medicine, 1782, from Latin expectorantem (nominative expectorans), present participle of expectorare (see expectorate). From 1811 as an adjective.
expectorate (v.): 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.): 1670s, noun of action from expectorate.
expediate (v.): a 17c. error for expedite that has gotten into the dictionaries.
expedience (n.): 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.): 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.): late 14c., from expedient (adj.) + -ly (2).
expedite (v.): 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.): 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.): 1803, from expedition + -ary.
expeditious (adj.): 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.): 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.): 1888, from expel + -ee.
expend (v.): 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.): 1805, from expend + -able.
expenditure (n.): 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.): 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.): 1909, from expense (n.). Related: Expensed; expensing.
expenses (n.): "charges incurred in the discharge of duty," late 14c. See expense (n.).
expensive (adj.): 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 (n.): 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 *per-yo-, suffixed form of root *per- (3) "to try, risk" (see peril). Meaning "state of having done something and gotten handy at it" is from late 15c.
experience (v.): 1530s, "to test, try, learn by practical trial or proof;" see experience (n.). Sense of "feel, undergo" first recorded 1580s. Related: Experienced; experiences; experiencing.
experienced (adj.): "having experience, taught by practice, skillful through doing," 1570s, past participle adjective from experience (v.).
experiential (adj.): 1640s (implied in experientially), from Latin experientia "knowledge gained by testing or trials" (see experience (n.)) + -al (1).
experiment (n.): 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.): late 15c., from experiment (n.). Intransitive sense by 1787. Related: Experimented; experimenting.
experimental (adj.): 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.): 1670s, noun of action from experiment (v.).
expert (adj.): 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.): 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.): "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: Latin, "take it from one who knows" ("Aeneid," xi.283); dative singular of expertus (see expert (adj.)) + imperative singular of credere (see credo).