Online Etymology Dictionary

highfalutin' (adj.): also high-falutin, 1839, U.S. slang, possibly from high-flying or high-flown, or even fluting. As a noun from 1848.
highland (n.): Old English heohlond "mountainous country;" see high (adj.) + land (n.). Highlands "mountainous district of Scotland" first recorded early 15c.
Highlander (n.): 1630s, from Highland + -er (1). Compare Dutch hooglander, German Hochländer.
highlight (n.): 1650s, originally of paintings, "the brightest part of a subject," from high (adj.) + light (n.). The figurative sense of "outstanding feature or characteristic" is from 1855. Hairdressing sense is 1941. Related: Highlights.
highlight (v.): 1861, from highlight (n.). Hairdressing sense is 1942. Related: Highlighted; highlighting.
highlighter (n.): "marking pen with transparent ink," 1963, agent noun from highlight (v.).
highly (adv.): Old English healice "nobly, gloriously, honorably;" see high (adj.) + -ly (1). Meaning "very, very much, fully" is mid-14c.
highness (n.): Old English heanes; see high (adj.) + -ness. Meaning "royalty, excellence, nobility" is early 13c.; Your Highness as a form of address to English royalty is attested from c. 1400.
hight (v.): "named, called" (archaic), from levelled past participle of Middle English highte, from Old English hatte "I am called" (passive of hatan "to call, name, command") merged with heht "called," active past tense of the same verb. Hatte was the only survival in Old English of the old Germanic synthetic passive tense. Proto-Germanic *hait- "to call, summon," also is the source of Old Norse heita, Dutch heten, German heißen, Gothic haitan "to call, be called, command," and is perhaps from the PIE root *keie- "to set in motion" (see cite).
highway (n.): Old English heahweg "main road from one town to another;" see high (adj.) in sense of "main" + way (n.). High street (Old English heahstræte) was the word before 17c. applied to highways and main roads, whether in the country or town, especially one of the Roman roads. In more recent usage, it generally is the proper name of the street of a town which is built upon a highway and was the principal street of the place. Highway robbery is from 1707; as a trivial expression for something too costly, 1886.
highwayman (n.): "one who travels the highways with intent to rob people" (often on horseback and thus contrasted to a footpad), 1640s, from highway + man (n.).
hijack (v.): 1922, American English, perhaps from high(way) + jacker "one who holds up" (agent noun from jack (v.)). Originally "to rob (a bootlegger, smuggler, etc.) in transit;" sense of "seize an aircraft in flight" is 1968 (also in 1961 variant skyjack), extended 1970s to any form of public transportation. Related: Hijacked; hijacking. Related: Hijacker.
hijinks (n.): also hi-jinks, high jinks, "boisterous capers, lively or boisterous sport," 1842, from name of games played at drinking parties (1690s). See jink.
hijra (n.): also hijrah, the more correct form of hegira.
hike (v.): 1809, hyke "to walk vigorously," an English dialectal word of unknown origin. A yike from 1736 answers to the sense. Not in widespread popular use until early 20c.
HIKE, v. to go away. It is generally used in a contemptuous sense. Ex. "Come, hike," i.e. take yourself off; begone. [Rev. Robert Forby, "The Vocabulary of East Anglia," London, 1830]
Sense of "pull up" (as pants) first recorded 1873 in American English, and may be a variant of hitch; extended sense of "raise" (as wages) is 1867. Related: Hiked; hiking.
hike (n.): 1865, from hike (v.).
hiker (n.): 1908, agent noun from hike (v.). Earlier as a type of boat:
The "hiker" or "tuck-up" as it is more generally termed, is a craft peculiar to the Delaware River, and is to the youth residing along the banks of that stream what the racing shell is to the Torontonian .... The origin of the name "hiker" is veiled in mystery. No member of the clubs engaged in sailing these boats can give anything like a satisfactory derivation of the word. The most common explanation is that it is corrupted from the local verb "to hike," which means to run or fly swiftly. ["Harper's Young People," 1885]
hilarious (adj.): 1823, "cheerful," from Latin hilaris "cheerful, lively, merry, joyful, of good cheer" (see hilarity) + -ous. Meaning "boisterously joyful" is from 1835. Related: Hilariously.
hilarity (n.): mid-15c., from Latin hilaritatem (nominative hilaritas) "cheerfulness, gaiety, merriment," from hilaris "cheerful, merry," from Greek hilaros "cheerful, merry, joyous," related to hilaos "graceful, kindly," and possibly from a suffixed form of the PIE root *sel- (2) "happy, of good mood" (see silly). In ancient Rome, Hilaria (neuter plural of hilaris) were a class of holidays, times of pomp and rejoicing; there were public ones in honor of Cybele at the spring equinoxes as well as private ones on the day of a marriage or a son's birth.
Hilary: masc. proper name, from Late Latin Hilarius, literally "cheerful," from Latin hilaris "cheerful" (see hilarity). The name was more popular in France than in England. The woman's name (Middle English Hillaria) seems to be this name merged with Eulalia, name of the patron saint of Barcelona, whose name is a Latinization of Greek eulalos "sweetly speaking." The Hilary sessions of British High Court and universities (1577) are from St. Hilarius, Bishop of Poitiers, obit. C.E. 368, eminent Church father and opponent of the Arians, whose feast day is Jan. 13, the Octave of the Epiphany.
Hilda: fem. proper name, German, literally "battle-maid," from fem. of Old High German hild "war, battle," from Proto-Germanic *hildiz "battle" (source also of Old English (poetic) hild "war, battle," Old Saxon hild, Old High German hilt, Old Norse hildr), from PIE *keldh-, from root *kel- (1) "to strike, cut" (see holt). Hild-/-hild was a common Germanic name-forming element; compare Hildebrand, Brunhild, Matilda.
Hildebrand: Germanic masc. proper name, Old High German Hildibrand, literally "battle-sword;" for first element see Hilda; for second element see brand (n.). The name of Gregory VII before he was pope (1073-85).
Hildegard: Germanic fem. proper name, Old High German Hildegard, literally "protecting battle-maid;" for first element see Hilda; for second element see yard (n.1).
hill (n.): Old English hyll "hill," from Proto-Germanic *hulni- (source also of Middle Dutch hille, Low German hull "hill," Old Norse hallr "stone," Gothic hallus "rock," Old Norse holmr "islet in a bay," Old English holm "rising land, island"), from PIE root *kel- (4) "to rise, be elevated, be prominent; hill" (source also of Sanskrit kutam "top, skull;" Latin collis "hill," columna "projecting object," culmen "top, summit," cellere "raise," celsus "high;" Greek kolonos "hill," kolophon "summit;" Lithuanian kalnas "mountain," kalnelis "hill," kelti "raise"). Formerly including mountains.
In Great Britain heights under 2,000 feet are generally called hills; 'mountain' being confined to the greater elevations of the Lake District, of North Wales, and of the Scottish Highlands; but, in India, ranges of 5,000 and even 10,000 feet are commonly called 'hills,' in contrast with the Himalaya Mountains, many peaks of which rise beyond 20,000 feet. [OED]

The term mountain is very loosely used. It commonly means any unusual elevation. In New England and central New York, elevations of from one to two thousand feet are called hills, but on the plains of Texas, a hill of a few hundred feet is called a mountain. [Ralph S. Tarr, "Elementary Geology," Macmillan, 1903]

Despite the differences in defining mountain systems, Penck (1896), Supan (1911) and Obst (1914) agreed that the distinction between hills, mountains, and mountain systems according to areal extent or height is not a suitable classification. ["Geographic Information Science and Mountain Geomorphology," 2004]
Figurative phrase over the hill "past one's prime" is first recorded 1950.
hill (v.): "cover with soil in the form of a hill, 1570s; "form into a hill," 1580s, from hill (n.). Related: Hilled; hilling.
hillbilly (n.): "southern Appalachian person," by 1892, from hill (n.) + Billy/Billie, popular or pet form of William.
I would hate to see some old railroad man come here and take my job, and then, I don't think it is right to hire some Hill Billy and give him the same right as I just because he was hired the same time I was. ["The Railroad Trainmen's Journal," vol. IX, July 1892]

In short, a Hill-Billie is a free and untrammelled white citizen of Alabama, who lives in the hills, has no means to speak of, dresses as he can, talks as he pleases, drinks whiskey when he gets it, and fires of his revolver as the fancy takes him. ["New York Journal," April 23, 1900]
In reference to a type of U.S. folk music, first attested 1924.
Hillel: masc. proper name, from Hebrew, literally "he praised."
hillock (n.): late 14c., hilloc "small hill, mound or heap of earth" (c. 1200 as a surname), from hill (n.) + Middle English diminutive suffix -oc.
hillside (n.): late 14c., from hill (n.) + side (n.).
hilltop (n.): c. 1400, from hill (n.) + top (n.).
hilly (adj.): late 14c., from hill (n.) + -y (2).
hilt (n.): Old English hilt "hilt, handle of a sword or dagger," from Proto-Germanic *helt (source also of Old Norse hjalt, Old High German helza "hilt," Old Saxon helta "oar handle"), of uncertain origin, possibly from PIE root *kel- (1) "to strike, cut" (see holt). Formerly also used in plural in same sense as singular. Up to the hilts "completely" is from 1670s.
hilum (n.): 1753 in botany, Latin, "little thing, shred, trifle," of unknown origin, said originally to have meant "the eye of a bean." Related: Hilar.
him (pron.): Old English him, originally dative masculine and neuter of he, from Proto-Germanic *hi- (see he). Beginning 10c. it replaced hine as masculine accusative, a process completed by 15c. The dative roots of the -m ending are retained in German (ihm) and Dutch (hem). Hine persists, barely, as the southern England dialectal 'un, 'n for "him."
Himalaya: from Sanskrit himalayah, literally "abode of snow," from hima "snow," from PIE *ghi-mo-, from a possible PIE base for "winter" (see hibernation) + alayah "abode," derivative of layate "sticks, stays," from PIE root *(s)lei- "sticky" (see lime (n.1)). Related: Himalayas; Himalayan.
himself (pron.): Old English him selfum, from dative/accusative personal pronoun him + self, here used as an inflected adjective.
hin (pron.): Old English hine, accusative of he; replaced by dative him in early Middle English. Cognate with German ihn. It is said to survive somewhat in southwest English and Kentish dialect.
hincty (adj.): "conceited," by 1924 in African-American vernacular. Compare obsolete Scottish hichty (c. 1500), considered an alteration of height-y.
hind (adj.): c. 1300, "pertaining to the rear, back, posterior," perhaps a back-formation from Old English behindan "back, behind," used as adverb and preposition (see behind), or from or influenced by Old English hindan (adv.) "from behind," from Proto-Germanic *hind- "behind" (cognate with Gothic hindan (prep.) "on that side of, beyond, behind;" German hinten "behind"), of unknown origin. Possibly influenced by Middle English hiner (adv.) "back, rear."
hind (n.): "female deer," Old English hind, from Proto-Germanic *hinthjo (source also of Old Norse hind, Dutch hinde, Old High German hinta, German Hindin (with added fem. suffix) "hind"). This is perhaps from PIE *kemti-, from root *kem- (1) "hornless" (source also of Greek kemas, Lithuanian smulas "young deer, gazelle," Old Norse skammr "short, brief").
hinder (v.): Old English hindrian "to harm, injure, impair, check, repress," from Proto-Germanic *hinderojan (source also of Old Norse hindra, Old Frisian hinderia, Dutch hinderen, Old High German hintaron, German hindern "to keep back"), derivative verb from a root meaning "on that side of, behind" (see hind (adj.)); thus the ground sense is "to put or keep back," though this sense in English is recorded only from late 14c. Related: Hindered; hindering.
hinder (adj.): "situated in the rear, pertaining to the rear, toward the back," late 14c., probably from an unrecorded Old English adjective from hinder (adv.) "behind, back, afterward," but treated as a comparative of hind (adj.). Related to Old High German hintar, German hinter, Gothic hindar "behind" (prep.).

Middle English had hinderhede, literally "hinder-hood; posterity in time, inferiority in rank;" and hinderling "person fallen from moral or social respectability, wretch," from an Old English term of contempt for a person devoid of honor. Also compare Scottish hinderlins "the buttocks."
hinderance (n.): early form of hindrance (q.v.).
hindermost (adj.): late 14c., hyndermest; see hinder (adj.) + -most. Middle English also had hindermore, which, as a noun, could mean "the hinder parts."
Hindi (adj.): 1825, from Hind "India" (see Hindu) + -i, suffix expressing relationship. As a the name of a modern language of India, 1880.
hindmost (adj.): "furthest at the rear," late 14c., from hind (adj.) + -most.
Thra. What, if a toy take 'em i' the heels now, and they run all away, and cry, 'The devil take the hindmost'?
Dion. Then the same devil take the foremost too, and souse him for his breakfast! [Beaumont & Fletcher, "Philaster," Act V, Scene 2, 1611]
Hindoo: former spelling of Hindu (q.v.).
hindrance (n.): mid-15c., a hybrid from hindren (see hinder (v.)) on model of French-derived words in -ance.
hindsight (n.): 1806, "backsight of a firearm," from hind (adj.) + sight (n.). Meaning "a seeing what has happened, a seeing after the event what ought to have been done" is attested by 1862, American English, (in proverbial "If our foresight was as good as our hindsight, it would be an easy matter to get rich"), probably formed as a humorous opposition to older foresight (q.v.).
Hindu (n.): 1660s, from Persian Hindu (adjective and noun) "Indian," from Hind "India," from Sanskrit sindhu "river," meaning here the Indus; hence "region of the Indus," the sense then gradually was extended by invading peoples to encompass all northern India. "Properly, one of the native race in India descended from the Aryan conquerors. ... More loosely, the name includes also the non-Aryan inhabitants of India" [Century Dictionary, 1902]. As an adjective from 1690s. The Hindu Kush mountain range is said to mean literally "Indian killer," and was said to have been the name given by the Persians to a pass where their Indian slaves had perished in winter, but this likely is folk etymology.