Online Etymology Dictionary

untempered (adj.): mid-15c., "not properly mixed, undiluted," from un- (1) "not" + past participle of temper (v.). Similar formation in Middle Dutch ongetempert, Middle High German ungetempert. Earlier as "unrestrained" (late 14c.), also, of a musical instrument, "not properly tuned;" meaning "unhardened" is from 1820.
unclear (adj.): c. 1300, "not easy to understand," from un- (1) "not" + clear (adj.). Similar formation in Middle Dutch onclaer, Dutch onklaar, German unklar, Old Norse uklarr, Danish uklar, Swedish oklar. Of persons, in sense of "uncertain, doubtful," it is recorded from 1670s.
unlucky (adj.): 1520s, "marked by misfortune or failure," from un- (1) "not" + lucky (adj.). Similar formation in West Frisian unlokkich, Mliddle Low German unluckich. Sense of "boding ill" is recorded from 1540s; that of "having bad luck" is from 1550s; that of "bringing bad luck" is from 1580s. Related: Unluckily; unluckiness.
unequal (adj.): 1530s, "unjust, unfair," from un- (1) "not" + equal (adj.). Meaning "not the same in amount, size, quality, etc." is recorded from 1560s (inequal in this sense is from late 14c.). Sense of "inadequate, insufficient" (to some task) is attested from 1690s. Related: Unequally.
unhappy (adj.): c. 1300, "causing misfortune or trouble (to oneself or others)," from un- (1) "not" + happy. Meaning "unfortunate, unlucky" is recorded from late 14c.; sense of "miserable, wretched" is recorded from late 14c. (originally via misfortune or mishap).
unattached (adj.): late 15c., "not arrested or seized," from un- (1) "not" + past participle of attach (v.). Meaning "not associated with any body or institution" is recorded from 1796; sense of "single, not engaged or married" is first attested 1874.
unarmed (adj.): c. 1300, "with armor removed," from un- (1) "not" + armed, or else past participle adjective from unarm "strip of armor" (c. 1300), from un- (2) "opposite of" + arm (v.). Meaning "not fitted to attack, weaponless" is from late 14c.
un-American (adj.): "not characteristic of American principles or methods, foreign to U.S. customs," 1818, from un- (1) "not" + American (adj.).
Everything is un-American that tends either to government by a plutocracy or government by a mob. [Theodore Roosevelt, 1917]
unaffected (adj.): 1580s, "not influenced, untouched in mind or feeling," from un- (1) "not" + past participle of affect (v.). Meaning "not adopted or assumed, genuine" is recorded from 1590s; that of "not acted upon or altered (by something)" is first attested 1830. Related: Unaffectedly; unaffectedness.
undue (adj.): late 14c., "not owing or payable; unjustly demanded," also "not appropriate, unseasonable," also "excessive," from un- (1) "not" + past participle of due (v.). Formed on model of Old French indeu, Latin indebitus.
Rio de Janeiro: literally "January River," named by explorer Amerigo Vespucci because he discovered it on Jan. 1, 1502, and so called because he incorrectly thought the bay was the estuary of a large river. See January.
affectionate (adj.): 1580s, "fond, loving," from affection + -ate (1). Early, now mostly obsolete, senses included "inclined" (1530s), "prejudiced" (1530s), "passionate" (1540s), "earnest" (c. 1600). Other forms also used in the main modern sense of the word included affectious (1580s), affectuous (mid-15c.).
asportation (n.): "a carrying away or off" (legal), c. 1500, from Latin asportationem (nominative asportatio), noun of action from past participle stem of asportare "to carry off," from abs- "away" (see ab-) + portare "to carry" (see port (n.1)).
astrologer (n.): late 14c., from astrology + -er (1). Drove out French import astrologein, which, had it survived, probably would have yielded *astrologian, as in Chaucer's "The wise Astrologen." Earliest recorded reference is to roosters as announcers of sunrise.
armchair (n.): also arm-chair, 1630s, from arm (n.1) + chair; adjective sense in reference to "criticism of matters in which the critic takes no active part" is from 1886. Another old name for it was elbow-chair (1650s).
Arthropoda (n.): 1870, Modern Latin, literally "those with jointed feet," coined 1845 by German zoologist Karl Theodor Ernst von Siebold (1804-1885) from Greek arthron "a joint" (see arthro-) + podos genitive of pous "foot," from PIE root *ped- (1) "a foot" (see foot (n.)).
arthritic (adj.): mid-14c., artetyk, "pertaining to arthritis," also as a noun, from Old French artetique (12c., Modern French arthritique), corresponding to Latin arthriticus, from Greek arthritikos, from arthron "joint" (see arm (n.1)). Spelling gradually restored to Latin form in 17c.
airlift (n.): also air-lift, 1893 as a type of pumping device; 1945 in the sense "transportation of supplies by air," from air (n.1) + lift (n.). As a verb by 1949; popularized in reference to the response to the West Berlin blockade. Related: Air-lifted; air-lifting.
anhedonia (n.): "inability to feel pleasure," 1897, from French anhédonie, coined 1896 by French psychologist Theodule Ribot (1839-1916) as an opposite to analgesia, from Greek an-, privative prefix (see an- (1)), + hedone "pleasure" (see hedonist) + abstract noun ending -ia.
stolid (adj.): c. 1600, back-formation from stolidity, or else from Middle French stolide (16c.), from Latin stolidus "insensible, dull, slow, brutish, rude, stupid," properly "unmovable," related to stultus "foolish," from PIE root *stel- "to put, stand" (see stall (n.1)).
satyagraha (n.): Indian form of passive resistance, 1920, in writings of M.K. Gandhi, from Sanskrit satyagraha "insistence on truth," from satya "truth, truthfulness" (from sat- "existing, true, virtuous," from PIE *es- "to be;" see essence) + agraha "pertinacity," from PIE *ghrebh- (1) "to seize, reach" (see grab (v.)).
saurian (n.): reptile of the order Sauria, 1819, from Modern Latin sauria "the order of reptiles," from Greek sauros "lizard" (see -saurus). Sauropod is 1891, from Modern Latin sauropoda (O.C. Marsh, 1884), second element from Greek pous "foot," from PIE root *ped- (1) "a foot" (see foot (n.)).
scalpel (n.): 1742, from Latin scalpellum "a surgical knife," diminutive of scalprum "knife, chisel, tool for scraping or cutting," from scalpere "to carve, cut," related to sculpere "to carve," from PIE root *(s)kel- "to cut, cleave" (see scale (n.1)).
stat (n.): "instrument that keeps something stationary," before 1970, shortened form of Latin statim (adv.) "steadily, regularly; at once, immediately," from status (see state (n.1)). Perhaps originally "to a standstill." As an abbreviation of statistic, from 1961. Related: Stats.
stere (n.): unit of the metric system for solid measure, 1798, from French stère "unit of volume equal to one cubic meter," from Greek stereos "solid, stiff, firm," from PIE root *ster- (1) "stiff, rigid" (see stereo-). Little used, cubic meter generally serving instead.
sacerdotal (adj.): c. 1400, from Old French sacerdotal and directly from Latin sacerdotalis "of or pertaining to a priest," from sacerdos (genitive sacerdotis) "priest," literally "offerer of sacrifices," from sacer "holy" (see sacred) + stem of dare "to give" (see date (n.1)).
sack (n.2): "a dismissal from work," 1825, from sack (n.1), perhaps from the notion of the worker going off with his tools in a bag; the original formula was to give (someone) the sack. It is attested earlier in French (on luy a donné son sac, 17c.) and Dutch (iemand de zak geven).
surcharge (v.): early 15c., "overcharge, charge too much expense," from Old French surcharger "to overload, overburden, overcharge" (12c.), from sur- "over" (see sur- (1)) + chargier "to load" (see charge (v.)). Meaning "make an extra charge on" is from 1885. The noun is also first attested early 15c. Related: Surcharged; surcharging.
surfeit (n.): early 14c., "excess quantity;" late 14c., "overindulgence," from Old French sorfet "excess; arrogance" (Modern French surfait), noun use of past participle of surfaire "overdo," from sur- "over" (see sur- (1)) + faire "do," from Latin facere "to make, do" (see factitious).
surmise (v.): c. 1400, in law, "to charge, allege," from Old French surmis, past participle of surmettre "to accuse," from sur- "upon" (see sur- (1)) + mettre "put," from Latin mittere "to send" (see mission). Meaning "to infer conjecturally" is recorded from 1700, from the noun. Related: Surmised; surmising.
surmount (v.): early 14c., "to rise above, go beyond," from Old French surmonter "rise above," from sur- "beyond" (see sur- (1)) + monter "to go up" (see mount (v.)). Meaning "to prevail over, overcome" is recorded from late 14c. Related: Surmounted; surmounting.
surrender (v.): mid-15c., "to give (something) up," from Old French surrendre "give up, deliver over" (13c.), from sur- "over" (see sur- (1)) + rendre "give back" (see render (v.)). Reflexive sense of "to give oneself up" (especially as a prisoner) is from 1580s. Related: Surrendered; surrendering.
copious (adj.): mid-14c., from Latin copiosus "plentiful," from copia "an abundance, ample supply, profusion, plenty," from com- "with" (see com-) + ops (genitive opis) "power, wealth, resources," from PIE root *op- (1) "to work, produce in abundance," (see opus). Related: Copiously.
copulate (v.): early 15c., "to join," from Latin copulatus, past participle of copulare "join together, couple, bind, link, unite," from copula "band, tie, link," from PIE *ko-ap-, from *ko(m)- "together" + *ap- (1) "to take, reach" (see apt). Sexual sense attested from 1630s. Related: Copulated; copulating.
cornea (n.): late 14c., from Medieval Latin cornea tela "horny web or sheath," from Latin cornu (genitive cornus) "horn," from PIE *ker- (1) "horn; head, uppermost part of the body" (see horn (n.)). So called for its consistency. Related: Corneal.
shelve (v.1): 1590s, "to overhang," also "to provide with shelves," probably a back-formation from shelves, plural of shelf (n.1). Meaning "put on a shelf" first recorded 1650s; metaphoric sense of "lay aside, dismiss" is from 1812. Related: Shelved; shelving.
scorpion (n.): c. 1200, from Old French scorpion (12c.), from Latin scorpionem (nominative scorpio), extended form of scorpius, from Greek skorpios "a scorpion," from PIE root *(s)ker- (1) "to cut" (see shear (v.)). The Spanish alacran "scorpion" is from Arabic al-'aqrab.
sinecure (n.): 1660s, "church benefice with an emolument but without parish duties," from Medieval Latin beneficium sine cura "benefice without care" (of souls), from Latin sine "without" (see sans) + cura, ablative singular of cura "care" (see cure (n.1)).
scrapple (n.): "scraps of pork and cornmeal seasoned, boiled, and pressed into large cakes," 1850, probably a diminutive form of scrap (n.1) with -el (2). Noted especially, and perhaps originally, as a regional favorite dish in and around Philadelphia, Pennsylvania.
screwball (n.): "eccentric person," 1933, U.S. slang, earlier as a type of erratic baseball pitch (1928), from a still earlier name for a type of delivery in cricket (1866), from screw (n.) + ball (n.1). Screwball comedy is attested from 1938, in reference to Carole Lombard.
Seleucid: 1803, in reference to dynasty founded in Syria 312 B.C.E. by Seleucus Nicator, general of Alexander. It lasted until the Roman conquest 65 B.C.E. The Seleucidan Era, a local reckoning in the East (maintained by Syrian Christians) usually is dated to Sept. 1, 312 B.C.E.
semper-: word-forming element meaning "always, ever," from Latin semper "always, ever, at all times, continuously" (literally "once for all"), from PIE *sem- (1) "one, as one, together" (source also of Latin semel "once," similis "like;" see same).
sentimental (adj.): 1749, "pertaining to or characterized by sentiment," from sentiment + -al (1). At first without pejorative connotations; meaning "having too much sentiment, apt to be swayed by prejudice" had emerged by 1793 (implied in sentimentalist). Related: Sentimentally.
atresia (n.): "occlusion of a natural passage in the body," 1807, from Modern Latin atresia, from Greek atretos "not perforated," from a-, privative prefix, + tresis "perforation," from PIE *tere- (1) "to rub, turn," with derivatives referring to boring and drilling (see throw (v.)).
Augustine (adj.): c. 1400 in reference to members of the religious order named for St. Augustine the Great (354-430), bishop of Hippo. The name is Latin Augustinus, from augustus "venerable, majestic, magnificent, noble" (see august (adj.)) + name-forming inus (see -ine (1)).
auscultate (v.): "to listen" (especially with a stethoscope), 1832, from Latin auscultatus, past participle of auscultare "to listen attentively to," from aus-, from auris "ear" (see ear (n.1)); "the rest is doubtful" [OED]. Tucker suggests the second element is akin to clinere "to lean, bend."
calcaneus (n.): from Latin (os) calcaneum "bone of the heel," from calcem (nominative calx (1)) "heel," a word of uncertain origin, perhaps from Etruscan. De Vaan lists as possible cognates Old Prussian culczi "hip," Lithuanian kulkšnis "ankle-(bone)" Bulgarian kalka "hip, thigh."
bossy (adj.): 1540s, "swelling, projecting and rounded, decorated with bosses" from boss (n.2). Meaning "domineering, fond of ordering people about" is recorded 1882, from boss (n.1) + -y (2). As a common cow name it represents Latin bos "cow" (see cow (n.)).
blackbird (n.): late 15c. (late 13c. as a surname), from black (adj.) + bird (n.1). OED says so called for being the only "black" (really dark brown) bird among the songbirds, reflecting an older sense of bird that did not include rooks, crows, ravens.
broaden (v.): 1727, from broad (adj.) + -en (1). The word seems no older than this date (discovered by Johnson in one of James Thomson's "Seasons" poems); broadened also is first found in the same poet, and past participle adjective broadening is recorded from 1850.