Online Etymology Dictionary

H: eighth letter of the alphabet; it comes from Phoenician, via Greek and Latin. In Phoenician it originally had a rough guttural sound like German Reich or Scottish loch. In Greek at first it had the value of Modern English -h-, and with this value it passed into the Latin alphabet via Greek colonies in Italy. Subsequently in Greek it came to be used for a long "e" sound; the "h" sound being indicated by a fragment of the letter, which later was reduced to the aspiration mark. In Germanic it was used for the voiceless breath sound when at the beginning of words, and in the middle or at the end of words for the rough guttural sound, which later came to be written -gh.

The sound became totally silent in Vulgar Latin and in the languages that emerged from it; thus the letter was omitted in Old French and Italian, but it was restored pedantically in French and Middle English spelling, and often later in English pronunciation. Thus Modern English has words ultimately from Latin with missing -h- (able, from Latin habile); with a silent -h- (heir, hour); with a formerly silent -h- now often vocalized (humble, humor, herb); and even a few with an excrescent -h- fitted in confusion to words that never had one (hostage, hermit). Relics of the formerly unvoiced -h- persist in pedantic insistence on an historical (object) and in obsolete mine host.

The pronunciation "aitch" was in Old French (ache "name of the letter H"), and is from a presumed Late Latin *accha (compare Italian effe, elle, emme), with the central sound approximating the rough, guttural value of the letter in Germanic. In earlier Latin the letter was called ha. The use in digraphs (as in -sh-, -th-) goes back to the ancient Greek alphabet, which used it in -ph-, -th-, -kh- until -H- took on the value of a long "e" and the digraphs acquired their own characters. The letter passed into Roman use before this evolution, and thus retained there more of its original Semitic value.
ha (interj.): natural expression of surprise, distress, etc.; early 14c., found in most European languages (including Latin and Old French) but not in Old English (which did, however, have ha-ha).
ha-ha: also haha, used of laughter since ancient times; Old English ha ha. Also in Greek (ha ha, in Euripides, Aristophanes), Latin (hahae). A different attempt at representation in English is py-hy (1580s). Sometimes interchanged with ah and expressing surprise, distress, etc. A ha-ha (1712), from French, was "an obstacle interrupting one's way sharply and disagreeably;" so called because it "surprizes ... and makes one cry Ah! Ah!" [Alexander Le Blond, "The Theory and Practice of Gardening," 1712].
habanera (n.): type of Cuban dance, 1874, literally "of Havana."
habeas corpus (n.): writ requiring a person to be brought before a court, mid-15c., Latin, literally "(you should) have the person," in phrase habeas corpus ad subjiciendum "produce or have the person to be subjected to (examination)," opening words of writs in 14c. Anglo-French documents to require a person to be brought before a court or judge, especially to determine if that person is being legally detained. From habeas, second person singular present subjunctive of habere "to have, to hold" (see habit (n.)) + corpus "person," literally "body" (see corporeal). In reference to more than one person, habeas corpora.
haberdasher (n.): early 14c. (late 13c. as a surname), "seller of small articles of trade" (caps, purses, beads, thread, stationery, etc.), from Anglo-French, where apparently it was an agent noun formation from hapertas "small wares," also a kind of fabric, a word of unknown origin. Sense of "dealer in men's wares" is 1887 in American English, via intermediate sense of "seller of caps." Middle English haberdash (n.) "small articles of trade sold by a haberdasher" appears to be a back-formation from this word, and the verb haberdash is late (1630s) and rare.
haberdashery (n.): early 15c., Anglo-French, "goods sold by a haberdasher," from haberdasher + -y (2). Meaning "a haberdasher's shop" is recorded from 1813, with perceived meaning shading to -ery.
habiliment (n.): often habiliments, early 15c., "munitions, weapons," from Middle French habillement, from abiller "prepare or fit out," probably from abile, habile "fit, suitable" (see able). Alternative etymology [Barnhart, Klein] makes the French verb originally mean "reduce a tree by stripping off the branches," from a- "to" + bille "stick of wood." Sense of "clothing, dress" developed late 15c., by association with habit (n.).
habilitate (v.): c. 1600 (transitive) "to qualify," from Medieval Latin habilitatus, past participle of habilitare, from habile "fit, suitable" (see able). Intransitive meaning "obtain necessary qualifications" is from 1881. Related: Habilitated; habilitation.
hability (n.): obsolete variant form of ability (see H).
habit (n.): early 13c., "characteristic attire of a religious or clerical order," from Old French habit, abit "clothing, (ecclesiastical) habit; conduct" (12c.), from Latin habitus "condition, demeanor, appearance, dress," originally past participle of habere "to have, hold, possess; wear; find oneself, be situated; consider, think, reason, have in mind; manage, keep," from PIE root *ghabh- "to give; to receive" (source also of Sanskrit gabhasti- "hand, forearm;" Old Irish gaibim "I take, hold, I have," gabal "act of taking;" Lithuanian gabana "armful," gabenti "to remove;" Gothic gabei "riches;" Old English giefan, Old Norse gefa "to give"). The basic sense of the root probably is "to hold," which can be either in offering or in taking.

Meaning "clothing generally" is from late 14c. Meaning "customary practice, usual mode of action" is early 14c. Drug sense is from 1887. The Latin word was applied to both inner and outer states of being, and both senses were taken in English, though meaning of "dress" now is restricted to monks and nuns. In 19c. it also was used of the costume worn by women when riding on horseback.
habit (v.): mid-14c., "to dwell, reside; dwell in" (obsolete), from Old French habiter, abiter "to dwell, inhabit; have dealings with," from Latin habitare "to live, dwell; stay, remain," frequentative of habere "to have, to hold, possess" (see habit (n.)). Meaning "to dress" is from 1580s. Related: Habited; habiting.
habitable (adj.): late 14c., from Old French habitable "suitable for human dwelling" (14c.), from Latin habitabilis "that is fit to live in," from habitare "to live, inhabit, dwell," frequentative of habere "to have, to hold, possess" (see habit (n.)).
habitant (n.): late 15c., "a dweller, a resident," from Old French habitant, abitant "inhabitant," from noun use of Latin habitantis, genitive plural of habitans, present participle of habitare "to live, inhabit, dwell," frequentative of habere "to have, to hold, possess" (see habit (n.)). Specific meaning "a native Canadian of French descent" attested by 1789; it was the usual word for small farmers in 18c. Quebec.
habitat (n.): "area or region where a plant or animal naturally grows or lives," 1762, originally a technical term in Latin texts on English flora and fauna, literally "it inhabits," third person singular present indicative of habitare "to live, inhabit, dwell," frequentative of habere "to have, to hold, possess" (see habit (n.)). This was the Modern Latin word that began the part of the scientific description of a plant or animal species that told its locality. General sense of "dwelling place" is first attested 1854.
habitation (n.): late 14c., "act or fact of dwelling;" also "place of lodging, abode," from Old French habitacion, abitacion "a dwelling; act of dwelling" (12c.) or directly from Latin habitationem (nominative habitatio) "a dwelling," noun of action from past participle stem of habitare "to live, inhabit, dwell," frequentative of habere "to have, to hold, possess" (see habit (n.)).
habitual (adj.): mid-15c., "customary, belonging to one's inherent disposition," from Medieval Latin habitualis "pertaining to habit or dress," from Latin habitus "condition, appearance, dress" (see habit (n.)).
habitually (adv.): mid-15c., from habitual + -ly (2).
habituate (v.): "accustom, make familiar," 1520s, from Late Latin habituatus, past participle of habituare "to bring into a condition or habit of the body," from Latin habitus "condition, appearance, dress" (see habit (n.)). Related: Habituated; habituating.
habituation (n.): mid-15c., "action of forming a habit; customary practice," from Medieval Latin habituationem (nominative habituatio), noun of action from past participle stem of Late Latin habituare "to bring into a condition or habit of the body," from Latin habitus "condition, appearance, dress" (see habit (n.)). Meaning "condition of being habituated" is from 1816.
habitude (n.): "customary manner, habit," c. 1400, from Old French habitude (14c.), from Latin habitudinem (nominative habitudo) "condition, appearance, habit," noun of state from past participle stem of habere "have, hold; manage, keep" (see habit (n.)). Related: Habitudinal (late 14c.).
habitue (n.): "habitual frequenter of" (some place), 1818, from French habitué, noun use of past participle of habituer "accustom," from Late Latin habituare "to bring into a condition or habit of the body," from Latin habitus "condition, appearance, dress" (see habit (n.)).
habnab (n.): variant of hobnob.
hacek (n.): diacritic used in Baltic and Slavic languages, 1953, from Czech háček, diminutive of hak "hook," from Old High German hako "hook," from Proto-Germanic *hoka- (see hook (n.)).
hacienda (n.): 1760, from American Spanish, "an estate or ranch in the country," from Spanish hacienda "landed estate, plantation," earlier facienda, from Latin facienda "things to be done," from facere "to do" (see factitious). For noun use of a Latin gerundive, compare agenda. The owner of one is a hacendado.

The change of Latin f- to Spanish h- is characteristic; compare hablar from fabulari, hacer from facere, hecho from factum, hermoso from formosum. Confusion of initial h- and f- was common in 16c. Spanish; the conquistador is known in contemporary records as both Hernando and Fernando Cortés.
hack (v.1): "to cut roughly, cut with chopping blows," c. 1200, from verb found in stem of Old English tohaccian "hack to pieces," from West Germanic *hakkon (source also of Old Frisian hackia "to chop or hack," Dutch hakken, Old High German hacchon, German hacken), from PIE *keg- "hook, tooth" (see hook (n.)). Perhaps influenced by Old Norse höggva "to hew, cut, strike, smite" (which is unrelated, from PIE *kau- "to hew, strike;" see hew). Slang sense of "cope with" (as in can't hack it) is first recorded in American English 1955, with a sense of "get through by some effort," as a jungle (phrase hack after "keep working away at" is attested from late 14c.). To hack around "waste time" is U.S. slang, by 1955, perhaps originally of golfers or cabbies. Related: Hacked; hacking.
hack (n.2): "person hired to do routine work," c. 1700, ultimately short for hackney "an ordinary horse, horse for general service (especially for driving or riding, as opposed to war, hunting, or hauling)," c. 1300. This word is probably from the place name Hackney, Middlesex. Apparently nags were raised on the pastureland there in early medieval times. Extended sense of "horse for hire" (late 14c.) led naturally to "broken-down nag," and also "prostitute" (1570s) and "a drudge" (1540s), especially a literary one, one who writes according to direction or demand. Sense of "carriage for hire" (1704) led to modern slang for "taxicab." As an adjective, 1734, from the noun. Hack writer is first recorded 1826, though hackney writer is at least 50 years earlier. Hack-work is recorded from 1851.
HACK. A hackney coach. The term hack is also frequently applied by women to any article of dress, as a bonnet, shawl, &c., which is kept for every day use. [Bartlett, "Dictionary of Americanisms," 1848]
hack (v.3): "to cough with a short, dry cough," 1802, perhaps from hack (v.1) on the notion of being done with difficulty, or else imitative.
hack (n.1): "tool for chopping," early 14c., from hack (v.1); cognates: Danish hakke "mattock," German Hacke "pickax, hatchet, hoe." Meaning "a cut, notch" is from 1570s. Meaning "an act of cutting" is from 1836; figurative sense of "a try, an attempt" is first attested 1898.
hack (v.2): "illegally enter a computer system," by 1984; apparently a back-formation from hacker. Related: Hacked; hacking (1975 in this sense). Earlier verb senses were "to make commonplace" (1745), "make common by everyday use" (1590s), "use (a horse) for ordinary riding" (1560s), all from hack (n.2).
hack (adj.): "hired, mercenary," 1812, from hack (n.2).
hack (n.3): "a short, hard cough," 1885, from hack (v.3).
hackamore (n.): halter chiefly used for breaking horses, 1850, American English, of uncertain origin. OED and Klein suggests a corruption of Spanish jaquima (earlier xaquima) "halter, headstall of a horse," which Klein suggests is from Arabic shakimah "bit of a bridle, curb, restraint."
hacker (n.): early 13c. (as a surname), "a chopper, cutter," perhaps also "one who makes hacking tools," agent noun from hack (v.1).

Meaning "one who gains unauthorized access to computer records" is attested by 1975, and this sense seems to suggest hack (v.1), but the computer use is said to be from slightly earlier tech slang sense of "one who works like a hack at writing and experimenting with software, one who enjoys computer programming for its own sake," reputedly a usage that evolved at Massachusetts Institute of Technology (however an MIT student from the late 1960s recalls hack (n.) being used then and there in the general sense of "creative prank." This suggests rather a connection with hack (n.2) via the notion of "plodding, routine work." There may be a convergence of both words here.
hackle (n.): Old English hacele "coat, cloak, vestment, mantle" (cognate with Old High German hachul, Gothic hakuls "cloak;" Old Norse hekla "hooded frock"), of uncertain origin. The same word with a sense of "bird plumage" is first recorded early 15c., though this might be from unrelated Middle English hackle "flax comb" (see heckle (n.)) on supposed resemblance of comb to ruffled feathers, or from an unrecorded continental Germanic word. Metaphoric extension found in phrases such as raise (one's) hackles (as a cock does when angry) is by 1881.
hackney (n.): "small saddle horse let out for hire," c. 1300, from place name Hackney (late 12c.), Old English Hacan ieg "Haca's Isle" (or possibly "Hook Island"), the "isle" element here meaning dry land in a marsh. Now well within London, it once was pastoral and horses apparently were kept there. Hence the use for riding horses, with subsequent deterioration of sense (see hack (n.2)). Old French haquenée "ambling nag" is an English loan-word.
hackneyed (adj.): "trite, so overused as to have become uninteresting," 1749, figurative use of past participle adjective from hackney (v.) "use a horse for riding" (1570s), hence "make common by indiscriminate use" (1590s), from hackney (n.), and compare hack (n.2) in its specialized sense of "one who writes anything for hire." From 1769 as "kept for hire."
hacksaw (n.): 1867, from hack (v.1) + saw (n.).
had: past tense and past participle of have, from Old English gehæfd. Assimilation of -f- to a following consonant is typical (as also in woman, lord, lady, head (n.), leman). Used since late Old English as an auxiliary to make pluperfect tense-phrases. You never had it so good (1946) was said to be the stock answer to any complaints about U.S. Army life.
haddock (n.): North Atlantic food fish of the cod family, late 13c., of unknown origin. Old French hadot and Gaelic adag, sometimes cited as sources, apparently were borrowed from English. OED regards the suffix as perhaps a diminutive.
hade (n.): "person; state, condition," Old English had "person, individual, character, individuality; condition, state, nature; sex, race, family, tribe;" see -hood. Obsolete after 14c. Cognate with Old Saxon hed "condition, rank, Old Norse heiðr "honor, dignity," Old High German heit, Gothic haidus "way, manner."
Hades: "god of the dead in Greek mythology;" also the name of his realm, the abode of the dead spirits, 1590s, from Greek Hades, Haides, in Homer the name of the god of the underworld, son of Kronos and Rhea, brother of Zeus and Poseidon. His name is of unknown origin. Perhaps literally "the invisible" [Watkins], from privative prefix a- + idein "to see" (see vision). The name of the god was extended in later Greek writing to his kingdom, also "the grave, death." Related: Hadal (adj.), 1964; Hadean.
Hadith (n.): "collected Islamic tradition, the body of traditions relating to Muhammad," 1817, from Arabic, literally "tradition," related to hadith "new, young," hadatha "it happened, occurred," and Hebrew hadash "new." Plural is Hadithat.
hadn't: by 1705, contraction of had not.
hadron (n.): 1962, from Greek hadros "thick, bulky" (the primary sense), also "strong, great; large, well-grown, ripe," from PIE root *sa- "to satisfy" (see sad). With elementary particle suffix -on. Coined in Russian as adron.
hadrosaur (n.): 1865, from Modern Latin hadrosaurus (1859), from Greek hadros "thick, stout" (see hadron) + -saurus.
hadst: archaic second person singular of had; a contraction of haddest.
hae (v.): an attempt to represent the Scottish pronunciation of have.
haematite (n.): see hematite; also see æ.
haemo-: see hemo-; also see æ.