Online Etymology Dictionary

compote (n.): 1690s, from French compote "stewed fruit," from Old French composte (13c.) "mixture, compost," from Vulgar Latin *composita, fem. of compositus (see composite). Etymologically the same word as compost (n.).
confinement (n.): 1590s, from French confinement (16c.; the Old French word was confinacion), from confiner (see confine). As a euphemism for "childbed" it dates from 1774 (the Middle English expression was Our Lady's bands).
conquest (n.): early 14c., a merged word from Old French conquest "acquisition" (Modern French conquêt), and Old French conqueste "conquest, acquisition" (Modern French conquête), both from past participle of conquerre, from Vulgar Latin *conquaerere (see conquer).
consensus (n.): 1854 as a term in physiology; 1861 of persons; from Latin consensus "agreement, accord," past participle of consentire (see consent (v.)). There is an isolated instance of the word from 1633.
cayuse (n.): "horse, Indian pony," 1841, American English, said to be a Chinook (native Pacific Northwest) word; also the name of an Indian group and language (1825), of unknown origin.
centi-: word-forming element meaning "one hundred" or "one hundredth part," used in English from c. 1800, from the French metric system, from Latin centi-, comb. form of centum "one hundred" (see hundred).
chanteuse (n.): "female singer of popular songs," 1888, from French chanteuse (16c.), fem. agent noun of chanter "to sing" (see chant (v.)). In Old French, the word was chanteresse.
Chad (n.2): African nation, former French colony (Tchad), independent since 1960, named for Lake Chad, which is from a local word meaning "lake, large expanse of water." An ironic name for such a desert country.
clearing-house (n.): also clearinghouse, 1832, from clearing + house (n.). The original was established 1775 in London by the bankers for the adjustment of their mutual claims for checks and bills; later the word was extended to similar institutions.
comical (adj.): early 15c., "comic," from comic (or Latin comicus) + -al (1). Meaning "funny" is from 1680s. Earlier Middle English had an identical word meaning "epileptic," from Latin morbus comitialis "epilepsy."
commodification (n.): 1968, from commodity + -fication. Originally in Marxist political theory, "the assignment of a market value," often to some quality or material the user of the word feels would be better without it.
befuddle (v.): "confuse," 1873, from be- + fuddle; originally "to confuse with strong drink or opium" (by 1832). An earlier word in the same sense was begunk (1725). Related: Befuddled; befuddling.
back up (v.): 1767, "stand behind and support," from back (v.) + up. The noun meaning "a standby, a reserve" is recorded from 1952 (often written as one word, backup); specific reference to computing is from 1965.
behavior (n.): late 15c., essentially from behave, but with ending from Middle English havour "possession," a word altered (by influence of have) from aver, noun use of Old French verb aveir "to have."
ventriloquist (n.): 1650s in the classical sense, from ventriloquy + -ist. In the modern sense from c. 1800. Ventriloquists in ancient Greece were Pythones, a reference to the Delphic Oracle. Another English word for them was gastromyth.
observer (n.): 1550s, "one who keeps a rule, custom, etc.," agent noun from observe. Meaning "one who watches and takes notice" is from 1580s; this is the sense of the word in many newspaper names.
opportunist (n.): 1881, from opportunism (q.v.) + -ist. A word in Italian politics, later applied in French by Rochefort to Gambetta (1876) and then generally in English to any who seek to profit from the prevailing circumstances.
manitou (n.): also manito, "spirit, deity, supernatural being," 1690s, from a word found throughout the Algonquian languages (Delaware manutoow, Ojibwa manidoo), first in English from Unami Delaware /manet:u/.
dilapidate (v.): 1560s, "to bring a building to ruin," from Latin dilapidatus, past participle of dilapidare "to squander, waste," originally "to throw stones, scatter like stones;" see dilapidation. Perhaps the English word is a back-formation from dilapidation.
dilation (n.): 1590s, formed from dilate on the mistaken assumption that the -ate in that word was the Latin verbal suffix (it is instead part of the stem); the proper form, dilatation, is older (c. 1400).
disadvantaged (adj.): 1610s, past participle adjective from disadvantage (v.). Of races or classes deprived of opportunities for advancement, from 1902, a word popularized by sociologists. As a noun, shorthand for disadvantaged persons, it is attested by 1939.
oligo-: before vowels olig-, word-forming element meaning "few, the few," from comb. form of Greek oligos "few, scanty, small, little," in plural, "the few;" of uncertain origin.
oxy-: word-forming element meaning "sharp, pointed; acid," from Greek oxy-, comb. form of oxys "sharp, pungent" (see acrid). Also used as a comb. form of oxygen.
geo-: word-forming element meaning "earth, the Earth," ultimately from Greek geo-, comb. form of Attic and Ionic ge "the earth, land, a land or country" (see Gaia).
hypomania (n.): "manic elation accompanied by quickened perception," 1843 (as a clinical word from 1882, from German hypomanie, 1881); see hypo- "under, beneath" + mania. Related: Hypomaniac; hypomanic.
-ible: word-forming element making adjectives from verbs, borrowed in Middle English from Old French -ible and directly from Latin adjective suffix -ibilis (properly -bilis); see -able.
-ide: word-forming element used to coin names for simple compounds of one element with another element or radical; originally abstracted from oxide, which was the first so classified.
hemato-: also haemato-, before vowels hemat-, haemat-, word-forming element in scientific compounds meaning "blood," from Greek haimato-, comb. form of haima (genitive haimatos) "blood" (see -emia). Compare hemo-.
hemo-: word-forming element meaning "blood," perhaps via Old French hemo-, Latin haemo-, from Greek haimo-, contraction of haimato-, comb. form of haima "blood" (see -emia).
hexa-: before vowels and in certain chemical compound words hex-, word-forming element meaning "six," from Greek hexa-, comb. form of hex "six," from PIE root *sweks- (see six).
homeless (adj.): "having no permanent abode," 1610s, from home (n.) + -less. Old English had hamleas, but the modern word probably is a new formation. As a noun meaning "homeless persons," by 1857.
headwaters (n.): attested 1530s, then not again until 1792 (in descriptions of Kentucky), so possibly the modern word is a re-formation; see head (n.) "origin of a river" + water (n.1).
gusset (n.): early 14c., from Old French gosset "armhole; piece of armor for the armpit" (13c.), apparently from gousse "shell of a nut," a word of unknown origin. Originally an armorer's term; of clothing from 1560s.
gyneco-: also gynaeco-, before a vowel gynec-, word-forming element meaning "woman, female," from Latinized form of Greek gynaiko-, comb. form of gyne "woman, female," from PIE root *gwen- "woman" (see queen).
mousetrap (n.): late 15c., from mouse (n.) + trap (n.). Figurative use from 1570s. The thing is older than the word. Old English had musfealle; Middle English had mouscacche (late 14c.).
hisself (pron.): c. 1400; a shift in felt meaning of the first element of himself (q.v.) from dative to genitive created this new word, but the same process did not change herself.
homie (n.): also homey, by 1970s, slang, short for homeboy (q.v.). OED reports the identical word is recorded from the 1920s in New Zealand slang in the sense "recently arrived British immigrant."
hunter (n.): mid-13c. (attested in place names from late 12c.), from hunt + -er (1). The Old English word was hunta, Middle English hunte. The hunter's moon (1710) is the next full moon after the harvest moon.
imitate (v.): 1530s, a back-formation from imitation or imitator, or else from Latin imitatus, past participle of imitari "to copy, portray." Related: Imitated; imitating. An Old English word for this was æfterhyrigan.
inauspicious (adj.): 1590s, from in- (1) "not, opposite of" + auspicious. Related: Inauspiciously; inauspiciousness. The Latin word was inauspicatus "without auspices; with bad auspices," which had a brief career in English as inauspicate (17c.).
incunabulum (n.): 1861, singular of Latin incunabula "cradle, birthplace; rudiments or beginnings" (see incunabula); taken up (originally in German) as a word for any book printed late 15c., in the infancy of the printer's art.
infinitude (n.): 1640s, from Medieval Latin *infinitudo, from Latin infinitus (see infinite) on model of multitudo, magnitudo. Or the English word is perhaps from or modeled on French infinitude (1610s).
intergalactic (adj.): 1928, in reference to galaxies as presently understood, from inter- + galactic. The word itself was in use by 1901, when galaxies were thought to be a sort of nebulae.
karst (n.): name of a high, barren limestone region around Trieste; used by geologists from 1894 to refer to similar landforms. The word is the German form of Slovenian Kras, which might be related to words in Slavic meaning "red."
gormless (adj.): c. 1746, also in early use gaumless, gawmless, "wanting sense, stupid," a British dialectal word, from gome "notice, understanding" (c. 1200), from Old Norse gaumr "care, heed" (of unknown origin); + -less.
gravitas (n.): 1924, usually in italics, from Latin gravitas "weight, heaviness;" figuratively, of persons, "dignity, presence, influence" (see gravity). A word wanted when gravity acquired a primarily scientific meaning.
electro-: before vowels electr-, word-forming element meaning "electrical, electricity," Latinized form of Greek elektro-, comb. form of elektron "amber" (see electric). As a stand-alone, formerly often short for electrotype, electroplate.
secretive (adj.): "inclined to secrecy," 1815 (implied in secretiveness); see secret (n.) + -ive. The word also was in Middle English with a sense "secret, hidden" (mid-15c.). Related: Secretively.
sleepless (adj.): early 15c., from sleep (n.) + -less. Old English had slæpleas but the modern word seems to be a re-formation. Similar formation in German schlaflos, Dutch slapeloos. Related: Sleeplessly; sleeplessness.
engineering (n.): 1720, "work done by an engineer," from engineer (n.). As a field of study, attested from 1792. An earlier word was engineership (1640s); engineery was attempted in 1793, but it did not stick.