Online Etymology Dictionary

Hopi: Pueblo people of the U.S. southwest, from Pueblo hopi, literally "well-mannered, civilized."
hoping (n.): c. 1300, verbal noun from hope (v.).
hoplite (n.): "heavy-armed foot soldier of ancient Greece," 1727, from Greek hoplites "heavy-armed," as a noun, "heavy-armed soldier, man-at-arms," from hopla "arms and armor, gear for war," plural of hoplon "tool, weapon, implement." One who carries a large shield, as opposed to a peltastes, so called for his small, light shield (pelte).
hopped (adj.): a word that seems to merge three senses of hop; the meaning "flavored with hops" (hop (n.1)) is first attested 1660s; that of "under the influence of drugs" (hop (n.2)) is from 1924; that of "excited, enthusiastic" (perhaps from hop (v.)) is from 1923. Meaning "performance-enhanced" (of an engine, etc.) is from 1945.
hopper (n.2): "container with a narrow opening at the bottom," late 13c., probably an agent noun from hop (v.1) via the notion of the grain juggling in a mill hopper or the mechanism itself, which was set to operate with a shaking motion. Railroad hopper-car is from 1862.
hopper (n.1): "person or animal that hops," mid-13c., agent noun from hop (v.). From c. 1200 as a surname, and perhaps existing in Old English (which had hoppestre "female dancer").
hopscotch (n.): children's game, 1801 (from 1789 as hop-scot), apparently from hop (v.) + scotch (n.2) "scratch," from the lines scored in the dirt to make the squares for the game.
Horace: masc. proper name, from French, from Latin Horatius, name of a Roman gens. The poet was Quintus Horatius Flaccus (65-8 B.C.E.). The form Horatio is influenced by the Italian version of the name, Orazio.
Horatian (adj.): 1750, from Horatius (see Horace) + -an, or from Latin Horatianus.
horde (n.): 1550s, "tribe of Asiatic nomads living in tents," from West Turkic (compare Tatar urda "horde," Turkish ordu "camp, army"), borrowed into English via Polish, French, or Spanish. OED says the initial -h- seems to have been acquired in Polish. Transferred sense of "any uncivilized gang" is from 1610s. Related: Hordes.
horde (v.): "to live or gather in hordes," 1821, from horde (n.). Related: Horded; hording.
hore (n.): "dirt, filth," also hor; from Old English horh "phlegm, mucus," horu "foulness, dirt, defilement," from Proto-Germanic *horwo- (source also of Old Frisian hore, Old High German horo, Old Norse horr), perhaps imitative of coughing up phlegm.
horizon (n.): late 14c., orisoun, from Old French orizon (14c., Modern French horizon), earlier orizonte (13c.), from Latin horizontem (nominative horizon), from Greek horizon (kyklos) "bounding (circle)," from horizein "bound, limit, divide, separate," from horos "boundary, landmark, marking stones." The h- was restored in English 17c. in imitation of Latin. Old English used eaggemearc ("eye-mark") for "limit of view, horizon." The apparent horizon is distinguished from the celestial or astronomical horizon.
horizontal (adj.): 1550s, "relating to or near the horizon," from French horizontal, from Latin horizontem (see horizon). Meaning "flat" (i.e., "parallel to the horizon") is from 1630s. As a noun also from 1550s. Related: horizontally.
hormonal (adj.): 1926, from hormone + -al (1). Earlier as a noun, the name of a spleen hormone. Related: Hormonally.
hormone (n.): "organic compound produced in animal bodies to regulate activity and behavior," 1905, from Greek hormon "that which sets in motion," present participle of horman "impel, urge on," from horme "onset, impulse," from PIE *or-sma-, from root *er- (1) "to move, set in motion." Used by Hippocrates to denote a vital principle; modern scientific meaning coined by English physiologist Ernest Henry Starling (1866-1927). Jung used horme (1915) in reference to hypothetical mental energy that drives unconscious activities and instincts. Related: Hormones.
horn (n.): Old English horn "horn of an animal; projection, pinnacle," also "wind instrument" (originally one made from animal horns), from Proto-Germanic *hurnaz (source also of German Horn, Dutch horen, Old Frisian horn, Gothic haurn), from PIE *ker- (1) "horn; head, uppermost part of the body," with derivatives refering to horned animals, horn-shaped objects and projecting parts (source also of Greek karnon "horn," Latin cornu "horn," Sanskrit srngam "horn," Persian sar "head," Avestan sarah- "head," Greek koryphe "head," Latin cervus "deer," Welsh carw "deer").

Late 14c. as "one of the tips of the crescent moon." The name was retained for a class of musical instruments that developed from the hunting horn; the French horn is the true representative of the class. Of dilemmas from 1540s; of automobile warning signals from 1901. Slang meaning "erect penis" is recorded by 1785. Jazz slang sense of "trumpet" is by 1921. Meaning "telephone" is by 1945. Figurative senses of Latin cornu included "salient point, chief argument; wing, flank; power, courage, strength." Horn of plenty is from 1580s. To make horns at "hold up the fist with the two exterior fingers extended" as a gesture of insult is from c.1600.

Symbolic of cuckoldry since mid-15c. (the victim was fancied to grow one on his head). The image is widespread in Europe and perhaps as old as ancient Greece. The German linguist Hermann Dunger ('Hörner Aufsetzen' und 'Hahnrei', "Germania" 29, 1884) ascribes it to a custom surviving into 19c., "the old practice of engrafting the spurs of a castrated cock on the root of the excised comb, which caused them to grow like horns" [James Hastings, "Encyclopedia of Religion and Ethics"] but the image could have grown as well from a general gesture of contempt or insult made to wronged husbands, "who have been the subject of popular jest in all ages" [Hastings].
horn (v.): 1690s, "to furnish with horns," from horn (n.). Earlier in figurative sense of "to cuckold" (1540s). Meaning "to push with the horns" (of cattle, buffalo, etc.) is from 1851, American English; phrase horn in "intrude" is by 1880, American English, originally cowboy slang. Related: Horned; horning.
horn-book (n.): also hornbook, 1580s, teaching tool consisting of a page with the alphabet, numerals, etc. written on it, fixed to a frame, and covered with transparent horn;" from horn (n.) + book (n.).
hornbeam (n.): type of small tree, 1570s, from horn (n.) + beam (n.) "tree," preserving the original sense of the latter word. The tree so called in reference to its hard wood, which somewhat resembles horn.
hornbill (n.): 1773, from horn (n.) + bill (n.2). So called from the horny casques atop the bills. Another old name for it was horned pie.
hornblende (n.): common dark mineral, 1770, from German Hornblende, from horn "horn of an animal" (see horn (n.)) + blende (see blende).
The term "Hornblende" is an old German name for any dark, prismatic crystal found with metallic ores but containing no valuable metal (the word "Blende" indicates "a deceiver") [Herbert Bucksch, "Dictionary Geotechnical Engineering," 1995]
Related: Horneblendic.
horndog (n.): by 1995, from horn (n.) in the sexual sense (see horny) + dog (n.).
horned (adj.): "furnished with horn or horns," Old English hyrned, from source of horn (n.). The modern word probably is a new formation in Middle English. From late 14c. in reference to Moses, and the horn-like rays of light, symbols of power, that appeared on his head as he descended Mount Sinai. From 1620s in reference to cuckolds. Horned toad is from 1766; horned question is "a dilemma" (1540s).
The HORNED TOAD is frightful ; his head half the size of his body ; his jaws open enormously ; his eye lids have the form of a pointed cone, which makes them seem armed with horns, wherein are his eyes. His feet have something the air of hands. [Francis Fitzgerald, "The General Genteel Preceptor," 1747]
horner (n.): c. 1300 "worker in horn" (maker of buttons, spoons, combs, etc.), from horn (n.). From mid-15c. as "one who blows a horn." Mid-13c. as a surname.
hornet (n.): Old English hyrnet, hurnitu "large wasp, beetle, gadfly," probably from Proto-Germanic *hurz-nut- (source also of Old Saxon hornut; Middle Dutch huersel, Dutch horzel (with diminutive suffix); Old High German hornaz, German Hornisse "hornet"), from a PIE imitative (buzzing) root; compare Old Church Slavonic srusa, Lithuanian szirszu "wasp." On this theory, the English word (as well as German Hornisse) was altered by influence of horn, to suggest either "horner" (from the sting) or "horn-blower" (from the buzz). Compare also Old Saxon hornobero "hornet," literally "trumpeter." Figurative of troublesome and persistent attacks.
horniness (n.): 1885, "degree to which something is or resembles horn;" by 1957 in the "state of advanced sexual excitement" sense; from horny + -ness.
hornless (adj.): late 14c., of animals; 1907 of phonograph players, from horn (n.) + -less.
hornpipe (n.): c. 1400, hornepype, musical instrument formerly used in England, with bell and mouthpiece made of horn, from horn (n.) + pipe (n.1). From late 15c. as the name of a lively country-dance (later especially popular with sailors) originally performed to music from such an instrument.
hornswoggle (v.): "to cheat," 1829, probably a fanciful formation. Related: Hornswoggled; hornswoggling.
horny (adj.): late 14c., "made of horn," from horn (n.) + -y (2). From 1690s as "callous, resembling horn." The colloquial meaning "lustful, sexually aroused," was in use certainly by 1889, perhaps as early as 1863; it probably derives from the late 18c. slang expression to have the horn, suggestive of male sexual excitement (but eventually applied to women as well); see horn (n.). As a noun it once also was a popular name for a domestic cow. For an adjective in the original sense of the word, hornish (1630s) and horn-like (1570s) are available.
horologer (n.): late 14c., "clock-maker," via Latin from Greek horologe "clock, timepiece, instrument for measuring the hours of a day," from horologos "telling the hour," from hora "hour" (see hour) on model of astrologer, etc. Hence also obsolete English horologe "timepiece, sundial, hourglass, clock, cock" (late 14c.) and the old expression the devil in the horologe for "mischief in an orderly system" (17c.).
horology (n.): science of time, 1752, a modern word coined from Greek hora "hour; part of the day; any period of time" (see hour) + -logy. "The term horology is at present more particularly confined to the principles upon which the art of making clocks and watches is established" [American edition of the "British Encyclopedia," Philadelphia, 1819]. Earlier in English it meant "clock, clock dial" (c. 1500), in which sense it represents Latin horologium "instrument for telling the hour" (in Medieval Latin, "a clock"), from Greek horologion "instrument for telling the hour" (a sundial, water-clock, etc.), from horologos "telling the hour." Related: Horologist (1795); horological (1590s). Horologiography (1630s) is the art or study of watches and timepieces.
horometry (n.): "art of the measurement of time," 1560s, from Greek hora "any time or period" (see hour) + -metry. Related: Horometrical; horometer.
horoscope (n.): "observation or diagram of the heavens, showing the positions of planets, on any given day, used by astrologers," mid-16c., from Middle French horoscope, from Latin horoscopum/horoscopus, from Greek horoskopos "nativity, horoscope," also "one who casts a horoscope, one who observes the hour of a birth," from hora "hour; season; period of time" (see hour) + skopos "watcher; what is watched" (see scope (n.1)). The notion is of "observing the hour" (of someone's birth, etc.). The word was in late Old English and Middle English as horoscopum, from Latin, but the modern form is considered to be a reborrowing. Related: Horoscopic; horiscopal. Horoscopy "the casting of a nativity" is attested from 1650s, from Latin horoscopium, from Greek horoskopeion, from horoscopia.
horrendous (adj.): 1650s, from Latin horrendus "dreadful, fearful, terrible," literally "to be shuddered at," gerundive of horrere "to bristle with fear, shudder" (see horror). Earlier form in English was horrend (mid-15c.).
horribile dictu: Latin, "horrible to say, dreadful to relate," from neuter of horribilis (see horrible) + ablative supine of dicere "to say, speak" (see diction).
horrible (adj.): c. 1300, "dreadful, terrible," from Old French horrible, orrible (12c.) "horrible, repugnant, terrifying," from Latin horribilis "terrible, fearful, dreadful" (source also of Spanish horrible, Portuguese horrivel, Italian orribile), from horrere "be terrified, bristle with fear, shudder" (see horror). Used as a mere intensifier from mid-15c.
horribly (adv.): mid-14c., from horrible + -ly (2). Colloquial sense of "exceedingly, intolerably" is from mid-15c.
horrid (adj.): early 15c., "hairy, shaggy, bristling," from Latin horridus "bristly, prickly, rough, horrid, frightful, rude, savage, unpolished," from horrere "to bristle with fear, shudder" (see horror). Meaning "horrible, causing horror" is from c. 1600. Sense weakened 17c. to "unpleasant, offensive."
[W]hile both [horrible and horrid] are much used in the trivial sense of disagreeable, horrible is still quite common in the graver sense inspiring horror, which horrid tends to lose .... [Fowler]
Related: Horridly.
horrific (adj.): "causing horror," 1650s, from French horrifique or directly from Latin horrificus "dreadful, exciting terror," literally "making the hair stand on end," from horrere "be terrified, bristle, to stand on end" (see horror) + -ficus, from stem of facere "to make, do" (see factitious). An older adjective was horriferous (1620s). Related: Horrifically.
horrify (v.): "cause to feel horror," 1802 (implied in horrified), from horror + -fy, or from Latin horrificare "cause horror." Related: Horrified.
horripilation (n.): 1650s, from Late Latin horripilationem (nominative horripilatio), noun of action from past participle stem of horripilare "bristle with hairs, be shaggy," from stem of horrere "to bristle" (see horror) + pilus "hair" (see pile (n.3)). The verb horripilate is attested from 1620s.
horror (n.): early 14c., "feeling of disgust;" late 14c., "emotion of horror or dread," also "thing which excites horror," from Old French horror (12c., Modern French horreur) and directly from Latin horror "dread, veneration, religious awe," a figurative use, literally "a shaking, trembling (as with cold or fear), shudder, chill," from horrere "to bristle with fear, shudder," from PIE root *ghers- "to bristle" (source also of Sanskrit harsate "bristles," Avestan zarshayamna- "ruffling one's feathers," Latin eris (genitive) "hedgehog," Welsh garw "rough").

Also formerly in English "a shivering," especially as a symptom of disease or in reaction to a sour or bitter taste (1530s); "erection of the hairs on the skin" (1650s); "a ruffling as of water surface" (1630s). As a genre in film, 1934. Chamber of horrors originally (1849) was a gallery of notorious criminals in Madame Tussaud's wax exhibition. Other noun forms are horribility (14c., now rare or disused), horribleness (late 14c.), horridity (1620s), horridness (1610s).
hors d'oeuvre: 1714, as an adverb, "out of the ordinary," from French hors d'oeuvre, "outside the ordinary courses (of a meal)," literally "apart from the main work," from hors, variant of fors "outside" (from Latin foris; see foreign) + de "from" + oeuvre "work," from Latin opera (see opus). Meaning "extra dish set out before a meal or between courses" attested in English from 1742.
hors de combat (adv.): 1757, French, literally "out of combat." Hors (prep.) "out, beyond," is from Latin foris (adv.) "outside," literally "out of doors" (see foreign). De is from Latin de "of." For combat see combat (n.). A similar expression from French is hors concours "out of competition" (1884), of a work of art in an exhibition.
horse (n.): "solidungulate perissodactyl mammal of the family Equidæ and genus Equus" [Century Dictionary], Old English hors "horse," from Proto-Germanic *hursa- (source also of Old Norse hross, Old Frisian, Old Saxon hors, Middle Dutch ors, Dutch ros, Old High German hros, German Roß "horse"), of unknown origin, connected by some with PIE root *kurs-, source of Latin currere "to run" (see current (adj.)).

The usual Indo-European word is represented by Old English eoh, Greek hippos, Latin equus, from PIE *ekwo- "horse" (see equine). In many other languages, as in English, this root has been lost in favor of synonyms, probably via superstitious taboo on uttering the name of an animal so important in Indo-European religion. For the Romanic words (French cheval, Spanish caballo) see cavalier (n.); for Dutch paard, German Pferd, see palfrey; for Swedish häst, Danish hest see henchman. As plural Old English had collective singular horse as well as horses, in Middle English also sometimes horsen, but horses has been the usual plural since 17c.

Used since at least late 14c. of various devices or appliances which suggest a horse (as in sawhorse), typically in reference to being "that upon which something is mounted." For sense of "large, coarse," see horseradish. Slang use for "heroin" is attested by 1950. To ride a horse that was foaled of an acorn (1670s) was through early 19c. a way to say "be hanged from the gallows." Horse latitudes first attested 1777, the name of unknown origin, despite much speculation. A dead horse as a figure for something that has ceased to be useful is from 1630s; to flog a dead horse "attempt to revive interest in a worn-out topic" is from 1864.
HORSEGODMOTHER, a large masculine wench; one whom it is difficult to rank among the purest and gentlest portion of the community. [John Trotter Brockett, "A Glossary of North Country Words," 1829]
The term itself is attested from 1560s. The horse's mouth as a source of reliable information is from 1921, perhaps originally of racetrack tips, from the fact that a horse's age can be determined accurately by looking at its teeth. To swap horses while crossing the river (a bad idea) is from the American Civil War and appears to have been originally one of Abe Lincoln's stories. Horse-and-buggy meaning "old-fashioned" is recorded from 1926 slang, originally in reference to a "young lady out of date, with long hair." To hold (one's) horses "restrain one's enthusiasm" is from 1854.
horse (v.): late Old English horsian "to provide with a horse or horses," from horse (n.). Related: Horsed; horsing. Sense of "to play excessive jokes on" is by 1893, mostly in formation horse around (1928), perhaps from horseplay, or from earlier nautical jargon use of the verb in reference to men, "drive or urge to work unfairly and tyrannically" (1867).
[A] favorite pastime for many men is to "horse" or guy a friend who has shown himself susceptible to ridicule or fun making. "Horsing" is extremely wholesome mental discipline for over sensitive or super-conceited young men. "Horsing" always implies a joke at another's expense. As to how it came into use there is no satisfactory theory to offer. ["Yale Literary Magazine," December 1893]
horse sense (n.): 1832, American English colloquial, from horse (n.), perhaps in referfence to the animal's qualities, or to the abilities of hostlers and coachmen with the animals, perhaps from the same association of "strong, large, coarse" found in horseradish.
horse-car (n.): 1863, from horse (n.) + car (n.).