Online Etymology Dictionary

hartebeest (n.): 1786, from Afrikaans, from Dutch hertebeest "antelope," from hert "hart" (see hart) + beest "beast, ox" (in S.African Dutch "steer, cattle"), from Middle Dutch beeste, from Old French beste "beast" (see beast).
hartshorn (n.): "ammonium carbonate," Old English heortes hornes, from hart + horn (n.). So called because a main early source of ammonia was the antlers of harts.
harum-scarum: 1670s (adv.), probably a compound of obsolete hare (v.) "harry" + scare (v.), with 'um as a reduced form of them. As an adjective from 1751; as a noun from 1784.
haruspex (n.): 1580s, from Latin haruspex (plural haruspices) "soothsayer by means of entrails," first element from PIE *ghere- "gut, entrail" (see yarn); second element from Latin spic- "beholding, inspecting" (see inspect). The practice is Etruscan. Related: Haruspical; haruspication.
Harvard: U.S. college named for John Harvard (1607-1638), Puritan immigrant minister who bequeathed half his estate and 260 books to the yet-unorganized college that had been ordered by the Massachusetts colonial government. The surname is cognate with Hereward, Old English hereweard, literally "army guard."
harvest (n.): Old English hærfest "autumn, period between August and November," from Proto-Germanic *harbitas (cf. Old Saxon hervist, Old Frisian and Dutch herfst, German Herbst "autumn," Old Norse haust "harvest"), from PIE *kerp- "to gather, pluck, harvest" (cf. Sanskrit krpana- "sword," krpani "shears;" Greek karpos "fruit," karpizomai "make harvest of;" Latin carpere "to cut, divide, pluck;" Lithuanian kerpu "cut;" Middle Irish cerbaim "cut").

The borrowing of autumn and the use of fall in a seasonal sense gradually focused the meaning of harvest to "the time of gathering crops" (mid-13c.), then to the action itself and the product of the action (after c.1300). Figurative use by 1530s. Harvest home (1590s) is the occasion of bringing home the last of the harvest; harvest moon (1706) is that which is full within a fortnight of the autumnal equinox.
harvest (v.): c.1400, from harvest (n.). Of wild animals, from 1947; of cells, from 1946. Related: Harvested; harvesting.
harvester (n.): "a reaper," 1590s; agent noun from harvest (v.). Meaning "machine for reaping and binding" is from 1847.
Harvey: masc. proper name introduced in England by Bretons at the Conquest; from Old French Hervé, Old Breton Aeruiu, Hærviu, literally "battle-worthy."
has (v.): third person singular present indicative of have. Has-been "one who has outlived his fame" first recorded c.1600 (as hes-beene).
hasenpfeffer (n.): 1892, from German hasenpfeffer, from Hase "hare" (see hare) + pfeffer "pepper" (see pepper).
hash (v.): 1650s, "to hack, chop into small pieces," from French hacher "chop up," from Old French hache "ax" (see hatchet). Hash browns is short for hash browned potatoes (1917), with the -ed omitted, as in mash potatoes. The hash marks on a football field were so called 1960s, from similarity to hash marks, armed forces slang for "service stripes on the sleeve of a military uniform" (1909), which supposedly were called that because they mark the number of years one has had free food (hash (n.1)) from the Army; but perhaps there is a connection with the noun form of hatch (v.2).
hash (n.2): short for hashish, 1959.
hash (n.1): "a stew," 1660s, from hash (v.). Meaning "a mix, a mess" is from 1735.
hashish (n.): 1590s, from Arabic hashish "powdered hemp," literally "dry herb," from hashsha "it became dry, it dried up."
Hasidic (adj.): also Chasidic, 1927, from Hasidim + -ic.
Hasidim: also Chasidim, 1812, adherents of a conservative Jewish religious movement founded 1750 by Rabbi Israel ben Eliezer Baal Shem Tobh, from Hebrew hasidhim, literally "pious ones," plural of hasidh "kind, pious." Earlier used in Hebrew of adherents of an anti-Hellenistic faction during the time of the Maccabean Wars.
hasp (n.): Old English hæpse "fastening, clip," with later Old English metathesis of -p- and -s-. Related to Old Norse hespa "hasp, fastening," Middle Dutch, German haspe "clamp, hinge, hook," of uncertain origin.
hassle (n.): 1945, American English, perhaps from U.S. Southern dialectal hassle "to pant, breathe noisily" (1928), of unknown origin; or perhaps from hatchel "to harass" (1800), which may be a variant of hazel, the name of the plant that furnished switches for whippings. Noted in 1946 as a show biz vogue word.
hassle (v.): 1951, from hassle (n.). Related: Hassled; hassling.
hassock (n.): Old English hassuc "clump of grass, coarse grass," of unknown origin. Sense of "thick cushion" is first recorded 1510s, with the likely connection being the perceived similarity of a kneeling cushion and a tuft of grass.
hast (v.): archaic second person singular present indicative of have.
hasta la vista: Spanish, literally "until the meeting (again)," salutation in parting.
hasta luego: Spanish, literally "until soon;" salutation in parting.
haste (n.): early 13c., from Old French haste "haste, urgency, hastiness" (12c., Modern French hâte), from Frankish *haifst "violence," from West Germanic *haifstiz (cf. Gothic haifsts "strife," Old English hæste "violent, vehement, impetuous"). To make haste is recorded by 1530s.
haste (v.): late 13c., from Old French haster (Modern French hâter), from haste (see haste). Now largely superseded by hasten (1560s).
hasten (v.): 1560s, extended form of haste (v.) with -en (1). Related: Hastened; hastening.
hastily (adv.): c.1300, "quickly," from hasty + -ly (2). Meaning "without due consideration" is 1580s.
Hastings: Old English Hæstingas "The Hastings; settlement of the family or followers of a man called *Hæsta;" literally "Hæsta's People."
The Hæstingas were an important tribal group referred to in an 8th cent. Northumbrian chronicle as the gens Hestingorum which seems to have kept a separate identity as late as the early 11th cent. ["Cambridge Dictionary of English Place-Names"]
hasty (adj.): mid-14c., "speedy, quick," by 1500s replacing or nativizing earlier hastif (c.1300) "eager, impetuous," from Old French hastif "speedy, rapid; forward, advanced; rash, impetuous" (12c., Modern French hâtif), from haste (see haste). Meaning "requiring haste" is late 14c. (the sense in hasty pudding, 1590s, so called because it was made quickly); that of "rash" is from early 15c. Related: Hastiness. Old French also had a form hasti (for loss of terminal -f, cf. joli/jolif, etc.), which may have influenced the form of the English word.
The termination was doubtless from the first identified with native -i, -y, from OE -ig; and it is noticeable that the other Teutonic langs. have formed corresponding adjs. of that type: Du. haastig, Ger., Da., Sw. hastig. [OED]
hat (n.): Old English hæt "hat, head covering," from Proto-Germanic *hattuz "hood, cowl" (cf. Frisian hat, Old Norse hattr), from PIE root *kadh- "cover, protect" (cf. Lithuanian kudas "tuft or crest of a bird," Latin cassis "helmet"). Now, "head covering with a more or less horizontal brim." To throw one's hat in the ring was originally (1847) to take up a challenge in prize-fighting. To eat one's hat is said to have been originally To eat Old Rowley's [Charles II's] hat.
hat trick (n.): 1879, originally from cricket, "taking three wickets on three consecutive deliveries;" extended to other sports (especially ice hockey) c.1909. Allegedly because it entitled the bowler to receive a hat from his club commemorating the feat (or entitled him to pass the hat for a cash collection), but also influenced by the image of a conjurer pulling things from his hat (attested by 1876). The term was used earlier for a different sort of magic trick:
Place a glass of liquor on the table, put a hat over it, and say, "I will engage to drink every drop of that liquor, and yet I'll not touch the hat." You then get under the table; and after giving three knocks, you make a noise with your mouth, as if you were swallowing the liquor. Then, getting from under the table, say "Now, gentlemen, be pleased to look." Some one, eager to see if you have drunk the liquor, will raise the hat; when you instantly take the glass and swallow the contents, saying, "Gentlemen I have fulfilled my promise: you are all witnesses that I did not touch the hat." ["Wit and Wisdom," London, 1860]
hatch (v.1): "to produce young from eggs by incubation," from Middle English hachen (early 13c.), probably from an unrecorded Old English *hæccan, of unknown origin, related to Middle High German, German hecken "to mate" (used of birds). Meaning "to come forth from an egg" is late 14c. Figurative use (of plots, etc.) is from early 14c. Related: Hatched; hatching.
hatch (n.): "opening," Old English hæc (genitive hæcce) "fence, grating, gate," from Proto-Germanic *hak- (cf. Middle High German heck, Dutch hek "fence, gate"). This apparently is the source of many of the Hatcher surnames; "one who lives near a gate." Sense of "plank opening in ship's deck" is first recorded mid-13c. Drinking phrase down the hatch first recorded 1931.
hatch (v.2): "engrave, draw fine parallel lines," late 14c., from Old French hachier "chop up, hack" (14c.), from hache "ax" (see hatchet). Related: Hatched; hatching. The noun meaning "an engraved line or stroke" is from 1650s.
hatchback: type of rear door of an automobile, 1970, from hatch (n.) + back (n.).
hatchery (n.): 1880, from hatch (v.1) + -ery.
hatchet (n.): c.1300 "small ax" (mid-12c. in surnames), from Old French hachete, diminutive of hache "ax, battle-axe, pickaxe," possibly from Frankish *happja or some other Germanic source, from Proto-Germanic *hæbijo (cf. Old High German happa "sickle, scythe"), from PIE root *kop- "to beat, strike" (cf. Greek kopis "knife;" Lithuanian kaplys "hatchet," kapoti "cut small;" Old Church Slavonic skopiti "castrate").

In Middle English, hatch itself was used in a sense "battle-axe." In 14c., hang up (one's) hatchet meant "stop what one is doing." Phrase bury the hatchet (1794) is from a supposed Native American peacemaking custom. Hatchet-man was originally California slang for "hired Chinese assassin" (1880), later extended figuratively to journalists who attacked the reputation of a public figure (1944).
hatchling (n.): 1854, from hatch (v.1) + diminutive suffix -ling.
hatchway (n.): 1620s, originally nautical, from hatch (n.) + way.
hate (v.): Old English hatian "to hate," from Proto-Germanic *hatojanan (cf. Old Saxon haton, Old Norse hata, German hassen, Gothic hatan "to hate"), from PIE root *kad- "sorrow, hatred" (cf. Avestan sadra- "grief, sorrow, calamity," Greek kedos "care, trouble, sorrow," Welsh cas "pain, anger"). Related: Hated; hating. French haine (n.), hair (v.) are Germanic. Hate crime attested from 1988.
hate (n.): Old English hete "hatred, spite," from Proto-Germanic *hatis- (cf. Old Norse hattr, Old Frisian hat, Dutch haat, Old High German has, German Hass, Gothic hatis; see hate (v.)). Altered in Middle English to conform with the verb. Hate mail is first attested 1967.
hateful (adj.): mid-14c., "full of hate;" late 14c., "exciting hate;" from hate + -ful. Related: Hatefully; hatefulness.
hater (n.): late 14c., "one who hates, an enemy," agent noun from hate (v.).
hath (v.): archaic third person singular present indicative of have.
Hathor: goddess of love and joy in ancient Egypt, from Greek Hathor, from Egyptian Het-Hert, literally "the house above," or possibly Het-Heru "house of Horus."
hatless (adj.): mid-15c., from hat + -less.
hatred (n.): early 13c., from hate + rare suffix -red, from Old English ræden "state, condition," related to verb rædan "to advise, discuss, rule, read, guess." See read and cf. second element of kindred and proper names Æþelræd and Alfred.
hatter (n.): late 14c., from hat + -er (1).
hauberk (n.): c.1300, from Old French hauberc "coat of mail," earlier holberc, from a Germanic source, perhaps Frankish *halsberg, literally "neck-cover" (cf. Old English halsbearh, Old High German halsberc), from hals "neck" (see collar) + bergan "to cover, protect."