Online Etymology Dictionary

jail (v.): "to put in jail, to confine as if in jail," c. 1600, from jail (n.). Related: Jailed; jailing.
jail-bait (n.): also jailbait, "girl under the legal age of consent conceived as a sex object," 1928, from jail (n.) + bait (n.).
jail-bird (n.): also jailbird, 1610s, based on an image of a caged bird; from jail (n.), which in its Middle English, French, and Latin ancestry also meant "cage" + bird (n.1).
jail-break (n.): also jailbreak, "prison escape," 1828, from jail (n.) + break (n.). Verbal phrase to break jail is from 1735.
jail-house (n.): also jailhouse, late 15c., from jail (n.) + house (n.). Earlier was jail-hall (late 14c.).
jailer (n.): also gaoler, late 14c., from Old North French gayolierre, Old French jaioleur (Modern French geôlier), agent noun from jaole/geole (see jail (n.)). Jail-keeper is attested from 1620s.
Jain (n.): 1805, from Hindi Jaina, from Sanskrit jinah "saint," literally "overcomer," from base ji "to conquer," related to jayah "victory," from PIE root *gweie- (2) "to press down; conquer." The sect dates from 6c. B.C.E.
Jainism (n.): 1858, from Jain + -ism. Jainist is attested from 1816.
Jake: colloquial or familiar abbreviation of the masc. proper name Jacob (q.v.). As the typical name of a rustic lout, from 1854. (Jakey still is the typical name for "an Amishman" among the non-Amish of Pennsylvania Dutch country). Slang meaning "excellent, fine" is from 1914, American English, of unknown origin.
jakes (n.): "a privy," mid-15c., genitive singular of jack (n.), perhaps a humorous euphemism.
jalapeno (n.): type of pepper, by 1957, literally "of Jalapa," from Mexican Spanish Jalapa, place in Mexico, from Aztec Xalapan, meaning "sand by the water," from xalli "sand" + atl "water" + -pan "place."
jalopy (n.): "battered old automobile," 1924 (early variants include jaloupy, jaloppi, gillopy), of unknown origin; perhaps from Jalapa, Mexico, where many U.S. used cars supposedly were sent (see jalapeno).
jalousie (n.): 1766, French, literally "jealousy" (see jealousy), from notion of spying through blinds without being seen.
jam (v.): "to press tightly" (trans.), 1719; "to become wedged" (intrans.), 1706, of unknown origin, perhaps a variant of Middle English cham "to bite upon something; gnash the teeth" (late 14c.; see champ (v.)). Of a malfunction in the moving parts of machinery by 1851. Sense of "cause interference in radio signals" is from 1914. Meaning "play in a jam session" is from 1935. Related: Jammed; jamming. The adverb is recorded from 1825, from the verb; jam-packed is from 1901, earlier jam-full (1830).
jam (n.1): "fruit preserve," 1730s, probably a special use of jam (v.) "press objects close together," hence "crush fruit into a preserve."
jam (n.2): "a tight pressing between two surfaces," 1806, from jam (v.). Sense of "machine blockage" is from 1890, which probably led to the colloquial meaning "predicament, tight spot," first recorded 1914. Jazz meaning "short, free improvised passage performed by the whole band" dates from 1929, and yielded jam session (1933); but this is perhaps from jam (n.1) in sense of "something sweet, something excellent."
Jamaica: West Indian island, from Taino (Arawakan) xaymaca, said to mean "rich in springs." Columbus when he found it in 1494 named it Santiago, but this did not stick. It belonged to Spain from 1509-1655, and after to Great Britain. Related: Jamaican.

The Jamaica in New York probably is a Delaware (Algonquian) word meaning "beaver pond" altered by influence of the island name.
jamb (n.): side-piece of an opening of a door, window, etc., early 14c., from Old French jambe "pier, side post of a door," originally "a leg, shank" (12c.), from Late Latin gamba "leg, (horse's) hock" (see gambol).
jambalaya (n.): 1849, from Louisiana French, from Provençal jambalaia "stew of rice and fowl."
jamboree (n.): 1866, "carousal, noisy drinking bout; any merrymaking," represented in England as a typical American English word, perhaps from jam (n.) on pattern of shivaree [Barnhart]. For the second element, Weekley suggests French bourree, a kind of rustic dance. Century Dictionary calls the whole thing "probably arbitrary." Klein thinks the word of Hindu origin (but he credits its introduction into English, mistakenly, to Kipling). Boy Scouts use is from 1920. It is noted earlier as a term in cribbage:
Jamboree signifies the combination of the five highest cards, as, for example, the two Bowers [jacks], Ace, King, and Queen of trumps in one hand, which entitles the holder to count sixteen points. The holder of such a hand, simply announces the fact, as no play is necessary; but should he play the hand as a Jambone, he can count only eight points, whereas he could count sixteen if he played it, or announced it as a Jamboree. ["The American Hoyle," New York, 1864]
Compare jambone "type of hand played by agreement in the card game of euchre."
James: masc. proper name, New Testament name of two of Christ's disciples, late 12c. Middle English vernacular form of Late Latin Jacomus (source of Old French James, Spanish Jaime, Italian Giacomo), altered from Latin Jacobus (see Jacob).

The Welsh form was Iago, the Cornish Jago. James the Greater (July 25) was son of Zebedee and brother of St. John; James the Less (May 1) is obscure and scarcely mentioned in Scripture; he is said to have been called that for being shorter or younger than the other. Fictional British spy James Bond dates from 1953, created by British author Ian Fleming (1908-1964), who plausibly is said to have taken the name from that of U.S. ornithologist James Bond (1900-1989), an expert on Caribbean birds.
Jamesian (adj.): "of or in the mode of James," 1875 in reference to William James (1842-1910), U.S. philosopher and exponent of pragmatism; 1905 in reference to his brother Henry James (1843-1916), U.S. expatriate novelist.
jams (n.): 1966, abstracted from pajamas (q.v.). Much earlier English picked up jam "a kind of frock for children" (1793) from Hindi jamah.
Jane: fem. proper name, from French Jeanne, Old French Jehane, from Medieval Latin Johanna (see John). As a generic name for "girl, girlfriend" it is attested from 1906 in U.S. slang. Never a top-10 list name for girls born in the U.S., it ranked in the top 50 from 1931 to 1956. It may owe its "everywoman" reputation rather to its association with the popular boy's name John.
Janet: fem. proper name, a diminutive of Jane with -et. In Middle English, Ionete-of-the-steues "Janet of the Stews" (see stew (n.)) was a common name for a prostitute (late 14c.).
jangle (v.): c. 1300, jangeln, "to talk excessively, chatter, talk idly" (intransitive), from Old French jangler "to chatter, gossip, bawl, argue noisily" (12c.), perhaps from Frankish *jangelon "to jeer" or some other Germanic source (compare Middle Dutch jangelen "to whine," Low German janken "to yell, howl"), probably imitative (compare Latin equivalent gannire). Meaning "make harsh noise" is first recorded late 15c. Transitive sense "cause to emit discordant or harsh sounds" is from c. 1600. Related: Jangled; jangling. Chaucer has jangler "idle talker, a gossip."
jangle (n.): late 13c., "gossip, slanderous conversation, dispute," from Old French jangle "idle chatter, grumbling, nagging," from jangler (see jangle (v.)). Meaning "discordant sound" is from 1795.
jangly (adj.): 1858, from jangle (n.) + -y (2).
janitor (n.): 1580s, "an usher in a school," later "doorkeeper" (1620s), from Latin ianitor "doorkeeper, porter," from ianua "door, entrance, gate," from ianus "arched passageway, arcade" (see Janus) + agent suffix -tor. Meaning "caretaker of a building, man employed to see that rooms are kept clean and in order" first recorded 1708. Fem. forms were janitress (1806), janitrix (1818).
janitorial (adj.): 1869, from janitor + -ial.
janizary (n.): also janisary, "elite Turkish infantry," 1520s, from Middle French janissaire (15c.), from Italian giannizzero, from Turkish yenicheri, literally "new troops," from yeni "new." The second element means "soldiery, but is said to have been conformed to the Italian form from an original Turkish asker (plural asakir) "army, soldier," from Arabic 'askar "army, troop." Formed 1362 from slaves and prisoners of war, until late 17c. largely recruited from converts to Islam and by compulsory conscription of Christian subjects. In later times Turks and other Muslims joined the corps because of the various privileges attached to it; it was abolished 1826. Related: Janizarian; Janisarian.
Jankin: masc. proper name, from Jan, variant of John, + diminutive suffix -kin. In Middle English, often applied contemptuously to priests.
Jansenism (n.): 1650s, in reference to doctrine of Cornelius Jansen (1585-1638), Catholic bishop of Ypres, who maintained the perverseness and inability for good of the natural human will. The term is prominent in 17c.-18c. religious writing, often as a reproach. The surname is the Flemish equivalent of Johnson. Related: Jansenist.
January (n.): late 13c., Ieneuer (early 12c. in Anglo-French), from Old North French Genever, Old French Jenvier (Modern French Janvier), from Latin Ianuarius (mensis) "(the month) of Janus," to whom the month was sacred as the beginning of the year according to later Roman reckoning (cognates: Italian Gennaio, Provençal Genovier, Spanish Enero, Portuguese Janeiro). The form was gradually Latinized by c. 1400. Replaced Old English geola se æfterra "Later Yule." In Chaucer, a type-name for an old man.
Janus: ancient Italic deity, to the Romans the guardian god of portals, doors, and gates; patron of beginnings and endings, c. 1500, from Latin Ianus, literally "gate, arched passageway," perhaps from PIE root *ei- (1) "to go" (cognates: Sanskrit yanah "path," Old Church Slavonic jado "to travel"). He is shown as having two faces, one in front the other in back (they may represent sunrise and sunset and reflect an original role as a solar deity). His temple in Rome was closed only in times of peace. Related: Janian.
JAP (n.): acronym for Jewish-American Princess, attested from 1971.
Jap (n.): colloquial abbreviation of Japanese, 1877, perhaps encouraged or inspired by the common abbreviation Jap.; it was not originally pejorative, but it became intensely so during World War II. It was protested by Japanese before the war, but did not begin to be taboo in the U.S. before 1960s. As an adjective from 1878. For some years after World War II in American English the word also functioned as a verb, "to execute a sneak attack upon," a reference to Pearl Harbor.
Japan: 1570s, via Portuguese Japao, Dutch Japan, acquired in Malacca from Malay Japang, from Chinese jih pun, literally "sunrise" (equivalent of Japanese Nippon), from jih "sun" + pun "origin." Japan lies to the east of China. Earliest form in Europe was Marco Polo's Chipangu.
japan (v.): "to coat with lacquer or varnish" in the manner of Japanese lacquer-work, 1680s, from Japan. Related: japanned; japanning. Hence also japonaiserie (1896, from French). Japanned work being generally black, japanned took on a slang sense of "ordained into the priesthood."
Japanese (adj.): 1580s, Iapones; see Japan + -ese. As a noun from c. 1600; meaning "the Japanese language" is from 1828. As nouns Purchas has Iaponite (1613), Hakluyt Japonian. The destructive Japanese beetle attested from 1919, accidentally introduced in U.S. 1916 in larval stage in a shipment of Japanese iris.
Japanesque (adj.): 1853, from Japan + -esque. In reference to aesthetics inspired by Japanese influence.
jape (v.): late 14c., "to trick, beguile, jilt; to mock," also "to act foolishly; to speak jokingly, jest pleasantly," perhaps from Old French japer "to howl, bawl, scream" (Modern French japper), of echoic origin, or from Old French gaber "to mock, deride." Phonetics suits the former, but sense the latter explanation. Chaucer has it in the full range of senses. Around mid-15c. the Middle English word took on a slang sense of "have sex with" and subsequently vanished from polite usage. It was revived in the benign sense of "say or do something in jest" by Scott, etc., and has limped along since in stilted prose. Related: Japed; japing.
jape (n.): mid-14c., "a trick, a cheat;" late 14c. "a joke, a jest; a frivolous pastime, something of little importance" (late 14c.); see jape (v.). By 1400 also "depraved or immoral act; undignified behavior; bawdiness." Related: Japery "jesting, joking, raillery, mockery" (mid-14c.).
Japheth: youngest of the three sons of Noah, from Late Latin Japheth, from Greek Iapheth, from Hebrew Yepheth, literally "enlargement," from causative form of the stem p-t-h "to be wide, spacious."
Japhetic (adj.): in reference to the presumed ancestral language of ancient Greek, Latin, and most of the modern European ones, 1730, from Biblical Japheth, a son of Noah, from whom the European peoples once were popularly supposed to have descended (as Middle Eastern Semitic from Shem; African Hamitic from Ham). Compare Aryan. Related: Japhetian (1752).
Japlish (n.): "unidiomatic English in Japan," 1960, from Japanese + English.
japonica (n.): "camellia," 1819, Modern Latin, fem. of japonicus "Japanese, of Japan," from Japon, a variant of Japan with a vowel closer to the Japanese name.
jar (v.): 1520s, "to make a brief, harsh, grating sound," often in reference to bird screeches; the word often is said to be echoic or imitative; compare jargon (n.), jay (n.), garrulous. Figurative sense of "have an unpleasant effect on" is from 1530s; that of "cause to vibrate or shake" is from 1560s. Related: Jarred; jarring. As a noun in this sense from 1540s.
jar (n.): "simple earthen or glass cylindrical vessel," early 15c., possibly from Old French jarre "liquid measure smaller than a barrel" (12c.), perhaps from Provençal jarra, from Arabic jarrah "earthen water vessel, ewer" (whence also Spanish jarra, Italian giarra), which is from Persian jarrah "a jar, earthen water-vessel."
jardiniere (n.): ornamental flower stand, 1841, from French jardinière "flower pot" (also "female gardener, gardener's wife"), noun use of fem. of adjective jardinier "of the garden," from jardin (see garden (n.)).