Online Etymology Dictionary

juicy (adj.): early 15c., from juice (n.) + -y (2). Figurative sense "weathly, full of some desired quality" is from 1620s; sense of "lively, suggestive, sensational" is from 1883. Related: Juiciness.
jujitsu (n.): also ju-jitsu, 1875, from Japanese jujutsu, from ju "softness, gentleness" (from Chinese jou "soft, gentle") + jutsu "art, science," from Chinese shu, shut.
juju (n.2): "marijuana cigarette," 1940, supposedly from reduplicated middle syllable of marijuana.
juju (n.1): object of religious veneration among West Africans, 1860, supposedly ultimately from French joujou "toy, plaything."
jujube (n.): late 14c., "date-like fruit from a tree found in Asia," from Medieval Latin jujuba (plural), from Late Latin zizyphum, from zizyphus, an Asiatic tree with datelike fruit, from Greek zizyphon, from Persian zayzafun. The meaning "soft candy with date-like flavor" first recorded 1835.
juke (n.): "roadhouse," 1935; see jukebox.
juke (v.): "to duck, dodge, feint," by 1971, variant of jook (q.v.). Related: Juked; juking.
jukebox (n.): 1937, jook organ, from jook joint "roadhouse" (1935), Black English slang, from juke, joog "wicked, disorderly," in Gullah (the creolized English of the coastlands of South Carolina, Georgia, and northern Florida), probably from Wolof and Bambara dzug "unsavory." Said to have originated in central Florida (see "A Note on Juke," Florida Review, vol. VII, no. 3, spring 1938). The spelling with a -u- might represent a deliberate attempt to put distance between the word and its origins.
For a long time the commercial juke trade resisted the name juke box and even tried to raise a big publicity fund to wage a national campaign against it, but "juke box" turned out to be the biggest advertising term that could ever have been invented for the commercial phonograph and spread to the ends of the world during the war as American soldiers went abroad but remembered the juke boxes back home. ["Billboard," Sept. 15, 1945]
julep (n.): late 14c., a syrupy drink in which medicine was given, from Old French julep (14c.), from Medieval Latin julapium, from Arabic julab, from Persian gulab "rose water," from gul "rose" (related to Greek rhodon, Latin rosa) + ab "water," from PIE root *ap- (see water (n.1)). Sense of "alcoholic drink flavored with mint" is first recorded 1787, American English.
Julia: fem. proper name, from Latin Iulia, fem. of Iulius (see Julius).
Julian (adj.): "old style" calendar, 1590s, in reference to reforms by Julius Caesar in 46 B.C.E. (see Julius). The masc. proper name is from Latin Iulianus, from Iulius.
Julie: fem. proper name, Anglicization of Julia.
julienne (n.): kind of clear soup, 1841, from French, literally "(soup made) in the manner of Julien," the proper name, from an otherwise unknown cook. Related: Julienned.
Juliet: fem. proper name, from Italian Giulietta, diminutive of Giulia "Julia" (see Julia). Cf. French Juliette. Juliet cap (1904) was felt to resemble a type worn in stage productions of "Romeo and Juliet."
A Parisian fancy which is finding little favor here, is the Juliet cap. It is a net of beads or of meshed cord jewelled or beaded at the intersections. Clustered bunches of blossoms and foliage are set at each side of the cap, above the ears. ["Fabrics, Fancy-Goods & Notions," trade publication, New York, January 1904]
Julius: masc. proper name, from Latin Iulius, name of a Roman gens, perhaps a contraction of *Iovilios "pertaining to or descended from Jove."
July: c.1050, Iulius, from Anglo-French julie, Old French Jule, from Latin Iulius "fifth month of the Roman calendar" (which began its year in March), renamed after his death and deification in honor of Gaius Julius Caesar, who was born in this month, which formerly in republican Rome was named Quintilis "fifth." Accented on first syllable in English until 18c. Replaced Old English liða se æfterra "later mildness," from liðe "mild."
jumble (v.): 1520s, originally "to move confusedly," perhaps coined on model of stumble, tumble, etc. In 17c., it was yet another euphemism for "have sex with" (a sense first attested 1580s). Meaning "mix or confuse" is from 1540s. Related: Jumbled; jumbling.
jumble (n.): "a confused mixture," 1660s, from jumble (v.).
jumbo (adj.): "very large, unusually large for its type," 1882, a reference to Jumbo, name of the London Zoo's huge elephant (acquired from France, said to have been captured as a baby in Abyssinia in 1861), sold February 1882 to U.S. circus showman P.T. Barnum amid great excitement in America and great outcry in England, both fanned by Barnum. The name is perhaps from slang jumbo "clumsy, unwieldy fellow" (1823), which itself is possibly from a word for "elephant" in a West African language (cf. Kongo nzamba).
"I tell you conscientiously that no idea of the immensity of the animal can be formed. It is a fact that he is simply beyond comparison. The largest elephants I ever saw are mere dwarfs by the side of Jumbo." [P.T. Barnum, interview, "Philadelphia Press," April 22, 1882]
As a product size, by 1886 (cigars). Jumbo jet attested by 1964.
jump (v.): 1520s, perhaps imitative (cf. bump); another theory derives it from words in Gallo-Romance dialects of southwestern France (cf. jumba "to rock, to balance, swing," yumpa "to rock"), picked up during English occupation in Hundred Years War. Superseded native leap, bound, and spring in most senses. Meaning "to attack" is from 1789; that of "to do the sex act with" is from 1630s. Related: Jumped; jumping. To jump to a conclusion is from 1704. Jumping-rope is from 1805. Jump in a lake "go away and stop being a pest" attested from 1912.
jump (n.): 1550s, "act of jumping," from jump (v.). Meaning "jazz music with a strong beat" first recorded 1937, in Count Basie's "One O'Clock Jump." Jump suit "one-piece coverall modeled on those worn by paratroopers and skydivers" is from 1948.
jumper (n.): 1610s, "one who jumps," agent noun from jump (v.). The word meaning "sleeveless dress" (1853) apparently is from mid-17c. jump "short coat," also "woman's under bodice," of uncertain origin, perhaps from French jupe "skirt" (see jupe). Meaning "sleeveless dress worn over a blouse" first recorded American English 1939.
jumpstart (v.): also jump-start, to start a car using battery booster cables, by 1970, from jumper "wire used to cut out part of a circuit or close a gap" (1901 in telegraphy); see jump + start. Related: Jumpstarted; jumpstarting. Figurative use by 1975.
jumpy (adj.): "nervous," 1869, from jump (n.) + -y (2). Related: Jumpiness.
jun: old abbreviation of junior.
junco (n.): 1706, from Spanish junco "reed, bush," as in junco ave "reed sparrow," a bird of the Indies.
junction (n.): 1711, "act of joining," from Latin iunctionem (nominative iunctio), noun of action from past participle stem of iungere "to join together" (see jugular). Meaning "place where things meet" first attested 1836, American English, originally in reference to railroad tracks.
juncture (n.): late 14c., "place where two things are joined," from Latin iunctura "a joining, uniting, a joint," from iunctus, past participle of iungere "to join" (see jugular). Sense of "point in time" first recorded 1650s, probably from astrology.
June: c.1100, from Latin Iunius (mensis), probably a variant of Iunonius, "sacred to Juno" (see Juno). Replaced Old English liðe se ærra "earlier mildness."
Juneau: city in Alaska, settled 1881 and named for prospector Joe Juneau.
junebug (n.): also june bug, 1829, name for various beetles which emerge in adult form and are active in June, first attested in Southern U.S. dialect, from June + bug (n.).
Jungian (adj.): 1933, "of or pertaining to the psychoanalytic school of Dr. Carl Gustav Jung" (1875-1961); for suffix, see -ian.
jungle (n.): 1776, from Hindi jangal "desert, forest, wasteland, uncultivated ground," from Sanskrit jangala-s "arid, sparsely grown with trees," of unknown origin. Specific sense of "land overgrown by vegetation in a wild, tangled mass" is first recorded 1849; meaning "place notoriously lawless and violent" is first recorded 1906, from Upton Sinclair's novel (cf. asphalt jungle, 1949, William R. Burnett's novel title, made into a film 1950 by John Huston; blackboard jungle, 1954, Evan Hunter's novel title, movie in 1955). Jungle gym was a trademark name, 1923, by Junglegym Inc., Chicago, U.S. Jungle bunny, derogatory for "black person," attested from 1966.
junior (adj.): late 13c., from Latin iunior, comparative of iuvenis "young, young man" (see young). Used after a person's name to mean "the younger of two" from late 13c. Abbreviation Jr. is attested from 1620s. Meaning "of lesser standing, more recent" is from 1766. That of "meant for younger people, of smaller size" is from 1860. Junior college first attested 1896; junior high school is from 1909. Junior miss "young teenage girl" is from 1907.
The junior high school is rapidly becoming the people's high school. The percentage of pupils completing the ninth year is constantly rising where junior high schools have been established. [Anne Laura McGregor, "Supervised Study in English for Junior High School Grades," New York, 1921]
junior (n.): 1520s, from junior (adj.).
juniority (n.): 1590s, from junior + -ity.
juniper (n.): "evergreen shrub," late 14c., from Latin iuniperus (source of French genièvre, Spanish enebro, Portuguese zimbro, Italian ginepro), of uncertain origin, perhaps related to iunco "reed." Watkins has it from PIE *yoini-paros "bearing juniper berries," from *yoi-ni- "juniper berry." Applied to various North American species from 1748. In the Bible, it renders Hebrew rethem, the name of a white-flowered shrub unrelated to the European evergreen.
Junius: masc. proper name, from Latin Junius, name of a Roman gens. The pseudonym of the author of a famous series of letters in the "Public Advertiser" from 1768-1772.
junk (n.1): "worthless stuff," mid-14c., junke "old cable or rope" (nautical), of uncertain origin, perhaps from Old French junc "rush, reed," also used figuratively as a type of something of little value, from Latin iuncus "rush, reed" (but OED finds "no evidence of connexion"). Nautical use extended to "old refuse from boats and ships" (1842), then to "old or discarded articles of any kind" (1884). Junk food is from 1971; junk art is from 1966; junk mail first attested 1954.
junk (n.2): "Chinese sailing ship," 1610s, from Portuguese junco, from Malay jong "ship, large boat" (13c.), probably from Javanese djong.
junk (v.): 1803, "to cut off in lumps," from junk (n.1). The meaning "to throw away as trash, to scrap" is from 1908. Related: Junked; junking.
New settlers (who should always be here as early in the spring as possible) begin to cut down the wood where they intend to erect their first house. As the trees are cut the branches are to be lopped off, and the trunks cut into lengths of 12 or 14 feet. This operation they call junking them; if they are not junked before fire is applied, they are much worse to junk afterwards. [letter dated Charlotte Town, Nov. 29, 1820, in "A Series of Letters Descriptive of Prince Edward Island," 1822]
junker (n.): "young German noble," 1550s, from German Junker, from Old High German juncherro, literally "young lord," from junc "young" (see young) + herro "lord" (see Herr). Pejorative sense of "reactionary younger member of the Prussian aristocracy" (1865) dates from Bismarck's domestic policy.
junket (n.): late 14c., "basket in which fish are caught or carried," from Medieval Latin iuncata "rush basket," perhaps from Latin iuncus "rush." Shifted meaning by 1520s to "feast, banquet," probably via notion of a picnic basket, which led to extended sense of "pleasure trip" (1814), and then to "tour by government official at public expense for no discernable public benefit" (by 1886, American English). Cf. Italian cognate giuncata "cream cheese" (originally made in a rush basket), a sense of junket also found in Middle English and preserved lately in dialects.
junkie (n.): "drug addict," 1923, from junk (n.1) in the narcotics sense + -y (3). Junker in the same sense is recorded from 1922. Junk for "narcotic" is older.
junky (adj.): "run-down, seedy, trashy," 1876, from junk (n.1) + -y (2).
Juno: Roman goddess of women and marriage, mid-14c., perhaps literally "the young one" (perhaps as goddess of the new moon), from an Italic root akin to Latin iunior "younger," iuvenis "young" (see young).
Junoesque (adj.): in reference to stately, mature beauty, 1861, from Juno + -esque. Qualities associated with the Roman goddess, who also was notable for her fits of rage.
junta (n.): 1620s, "Spanish legislative council," from Spanish and Portuguese junta "council, meeting, convention," from Medieval Latin iuncta "joint," from Latin iuncta, fem. past participle of iungere "to join" (see jugular).

Meaning "political or military group in power" first recorded 1640s as junto (from confusion with Spanish nouns ending in -o), originally with reference to the Cabinet Council of Charles I. Modern spelling in this sense is from 1714; popularized 1808 in connection with councils formed across Spain to resist Napoleon.
junto (n.): 1640s, erroneous formation of junta on model of Spanish nouns ending in -o.
jupe (n.): late 13c., "men's loose jacket," from Old French jupe, from Arabic jubbah "loose outer garment. As a woman's bodice, from 1810.