Online Etymology Dictionary

jowl (n.1): "jaw, jawbone," especially the underjaw, a late 16c. alteration of Middle English chawl (late 14c.), earlier chafle (c. 1200), from late Old English ceafl "jaw; cheek; jawbone; cheekbone," from Proto-Germanic *kefalaz (source of Middle High German kiver, German kiefer, Old Norse kjoptr "jaw," Danish kæft, Flemish kavel, Dutch kevel "gum"), from PIE *gep(h)- "jaw, mouth" (cognates: Old Irish gop, Irish gob "beak, mouth").

The spelling with j-, attested from c. 1400, is perhaps from influence of the synonymous Old French joue, which also was in Middle English (see jaw (n.)). This word and jowl (n.2) have influenced one another in form and sense. Middle English also had a jolle (late 14c.) meaning "the head," especially that of a fish, which might be from either or both nouns.
jowl (n.2): "fold of flesh under the jaw," 1590s, alteration of Middle English cholle "fold of flesh hanging from the neck or jaw, double chin" (c. 1300), which is perhaps from or related to Old English ceole "throat" (from PIE root *gwele- (3) "to swallow;" see gullet), but the phonetic development would be abnormal. Also see jowl (n.1).
jowly (adj.): 1860, from jowl (n.2) + -y (2). Related: Jowliness.
joy (n.): c. 1200, "feeling of pleasure and delight;" c. 1300, "source of pleasure or happiness," from Old French joie "pleasure, delight, erotic pleasure, bliss, joyfulness" (11c.), from Latin gaudia "expressions of pleasure; sensual delight," plural of gaudium "joy, inward joy, gladness, delight; source of pleasure or delight," from gaudere "rejoice," from PIE root *gau- "to rejoice" (cognates: Greek gaio "I rejoice," Middle Irish guaire "noble").

As a term of endearment from 1580s. Joy-riding is American English, 1908; joy-ride (n.) is from 1909.
joy-stick (n.): also joystick, 1910, aviators' slang for the control lever of an airplane, from joy + stick (n.). Transferred sense of "small lever to control movement" is from 1952; later especially in reference to controlling images on a screen (1978).
Joyce: proper name, earlier Josse, Goce, etc., and originally given to both men and women. Of Celtic origin. Joycean, in reference to the fiction of Irish writer James Joyce (1882-1941) is attested from 1927.
joyful (adj.): mid-13c., from joy + -ful. Related: Joyfully; joyfulness.
joyless (adj.): mid-14c., from joy + -less. Related: Joylessly; joylessness.
joyous (adj.): c. 1300, from Anglo-French joyous, Old French joios "happy, cheerful, merry, glad" (12c., Modern French joyeux), from joie (see joy). Related: Joyously; joyousness.
Juan: masc. proper name, Spanish form of John.
jubate (adj.): "having a mane," 1826, from Latin jubatus "maned," from juba "a mane, flowing hair on the neck of an animal," perhaps from a PIE root meaning "that moves" on the notion of "moving to and fro, shaking." This old guess has been rejected by some, "but since a better etymology is absent, we may accept it for the time being" [de Vaan].
jubilance (n.): "gladness, exultation," 1860, from jubilant + -ance.
jubilant (adj.): 1660s (Milton), from Latin iubilantem (nominative iubilans), present participle of iubilare "to let out whoops," in Christian writers, "to shout for joy," related to iubilum "wild shout," from Proto-Italic *iu, an exclamation of joy that probably was in Proto-Indo-European (cognates: Greek iu, an interjection of amazement, iuge "crying;" Middle High German ju, juch, an exclamation of joy; Dutch juichen, Old Norse yla, English yowl). With ending as in sibilant. Related: Jubilantly.
jubilate (v.): "make a joyful noise," 1640s, from Latin iubilatus, past participle of iubilare "shout for joy" (see jubilant). Related: Jubilated; jubilating.
jubilation (n.): late 14c., from Old French jubilacion "jubilation, rejoicing," and directly from Late Latin iubilationem (nominative iubilatio) "a shouting for joy," noun of action from past participle stem of iubilare "to let out whoops, shout for joy" (see jubilant).
jubilee (n.): late 14c., in the Old Testament sense, from Old French jubileu "jubilee; anniversary; rejoicing" (14c., Modern French jubilé), from Late Latin iubilaeus "the jubilee year," originally an adjective, "of the jubilee," from Greek iabelaios, from iobelos, from Hebrew yobhel "jubilee," formerly "a trumpet, ram's horn," literally "ram." The original jubilee was a year of emancipation of slaves and restoration of lands, to be celebrated every 50th year (Levit. xxv:9); it was proclaimed by the sounding of a ram's horn on the Day of Atonement.

The form of the word was altered in Latin by association with unrelated Latin iubilare "to shout with joy" (for which see jubilant), and the confusion of senses has continued in the Romanic languages and English. The general sense of "season of rejoicing" is first recorded mid-15c. in English, however through early 20c. the word kept its specific association with 50th anniversaries. As a type of African-American folk song, it is attested from 1872. The Catholic Church sense of "a period for remission of sin penalties in exchange for pilgrimages, alms, etc." was begun in 1300 by Boniface VIII.
Judaeo-: also Judeo-, word-forming element meaning "of or pertaining to the Jewish people or religion," from Latin Iudaeus (see Jew (n.)).
Judaeophobia (n.): "fear or hatred of the Jews; dread of their influence and opposition to their citizenship," 1881, from Judaeo- + -phobia. Related: Judaeophobe; Judaeophobic.
Judah: masc. proper name, biblical son of Jacob by Leah, also the name of a tribe of Israel, from Hebrew Yehudah, from stem of y-d-h, literally "praised."
Judaic (adj.): 1610s, from Middle French judaïque (15c.), and directly from Latin Iudaicus, from Greek Ioudaikos, from Ioudaios "Jew" (see Jew). Earlier in same sense was Judaical (late 15c.).
Judaism (n.): c. 1400 (attested in Anglo-Latin from mid-13c.), from Old French Judaisme and directly from Late Latin Judaismus, from Greek Ioudaismos, from Ioudaios "Jew" (see Jew). The Anglo-Latin reference is from a special tax levied on the Jews of England. Earlier in same sense was Juhede "Jewish faith, Judaism," literally "Jew-hood" (early 14c.).
Judas: biblical betrayer of Christ, Latin form of Greek Ioudas, from Hebrew Yehudha (see Judah). He was supposed to have had red hair. As a name for a malicious traitor, it is attested from late 15c. Judas priest as an exclamation in place of "Jesus Christ" is from 1914. Judas tree (1660s) supposedly was the type from which Judas hanged himself. The Judas goat (1941) leads sheep to the shackling pen.
Jude: masc. proper name, Hellenized form of Judah (q.v.), maintained in the Bible for the names of two disciples of Christ, to distinguish them from Judas (q.v.).
Judea: also Judaea, from Latin Iudaea, from Judah (see Judah). Related: Judean; Judaean.
judge (v.): c. 1200, iugen, "examine, appraise, make a diagnosis;" c. 1300, "to form an opinion about; inflict penalty upon, punish; try (someone) and pronounce sentence," also intransitive, "make a decision, decide, think, suppose;" from Anglo-French juger, Old French jugier "to judge, pronounce judgment; pass an opinion on" (10c., Modern French juger), from Latin iudicare "to judge, to examine officially; form an opinion upon; pronounce judgment," from iudicem (nominative iudex) "a judge," a compound of ius "right, law" (see just (adj.)) + root of dicere "to say" (see diction).

Related: Judged; judging. Spelling with -dg- emerged mid-15c. The Old English word was deman (see doom (n.)). The Latin word also is the source of Spanish juzgar, Italian giudicare.
judge (n.): mid-14c., "public officer appointed to administer the law" (early 13c. as a surname), also judge-man; from Old French juge, from Latin iudex "one who declares the law" (source also of Spanish juez, Italian giudice; see judge (v.). Extended from late 14c. to persons to decide any sort of contest; from 1550s as "one qualified to pronounce opinion." In Jewish history, it refers to a war leader vested with temporary power (as in Book of Judges), from Latin iudex being used to translate Hebrew shophet.
judgement (n.): see judgment. Related: Judgemental.
judger (n.): mid-15c., agent noun from judge (v.).
judgeship (n.): 1670s, from judge (n.) + -ship.
judgment (n.): mid-13c., jugement, "action of trying at law, trial," also "capacity for making decisions," from Old French jugement "legal judgment; diagnosis; the Last Judgment" (11c.), from jugier "to judge" (see judge (v.)).

From late 13c. as "penalty imposed by a court;" early 14c. as "any authoritative decision, verdict in a court case." From late 14c. in reference to the final trial of the human race in a future state (Judgment Day attested from late 14c.). Also from c. 1300 as "opinion." Sense of "discernment" is first recorded 1530s. By 1610s as "a divine allotment, event regarded as an expression of divine displeasure."
judgmental (adj.): 1873, "involving the exercise of judgment," from judgment + -al (1). Meaning "inclined to make moral judgments" is attested from 1952. Related: Judgmentally.
judicable (adj.): 1640s, from Late Latin iudicabilis "that can be judged," from iudicare "to judge," which is related to iudicem "a judge" (see judge (v.)).
judication (n.): 1620s, "action of judging," from Latin iudicationem (nominative iudicatio), noun of action from past participle stem of iudicare "to judge," related to iudicem "a judge" (see judge (v.)).
judicative (adj.): "having the ability to judge or form opinions," 1640s, from Latin iudicat-, past participle stem of iudicare "to judge," which is related to iudicem "a judge" (see judge (v.)) + -ive.
judicatory (n.): "court of judicature," 1570s, from noun use of Late Latin iudicatorius "judicial, pertaining to judging," from iudicat-, past participle stem of Latin iudicare "to judge," related to iudicem "a judge" (see judge (v.)). As an adjective, 1640s, from French judicatoire.
judicature (n.): 1520s, "legal power of administering judgment," from Medieval Latin iudicatura, from iudicat-, past participle stem of Latin iudicare "to judge" (see judge (v.)). For ending see -ure. Meaning "extent of jurisdiction of a judge or court" is from 1847.
judicial (adj.): late 14c., "of or pertaining to a judge; pertaining to the administration of justice," from Latin iudicalis "of or belonging to a court of justice," from iudicium "judgment, decision of a court of justice," also the court itself, from iudex "a judge" (see judge (v.)). Related: Judicially.
judiciary (adj.): "relating to courts," early 15c., from Latin iudiciarius "of or belonging to a court of justice," from iudicium "judgment, court of justice," from iudicem "a judge" (see judge (v.)). The noun meaning "a body of judges, judges collectively" is from 1788 (judicature was used in this sense from 1590s).
judicious (adj.): c. 1600, "having sound judgment; careful, prudent," also "manifesting sound judgment, carefully planned," from Middle French judicieux (16c.) or directly from Medieval Latin iudiciosus "prudent, judicious," from Latin iudicium "judgment," from iudicem "a judge" (see judge (v.)). Related: Judiciously; judiciousness.
Judith: fem. proper name, from Latin, from Greek Ioudith, from Hebrew Yehudith, fem. of Yehudha, literally "son of Judah" (see Judah). Judy is a pet form of it.
judo (n.): 1889, from Japanese judo, literally "gentle way," from ju "softness, gentleness" (from Chinese jou "soft, gentle") + do "way, art," from Chinese tao "way." "A refined form of ju-jitsu introduced in 1882 by Dr. Jigoro Kano, using principles of movement and balance, and practiced as a sport or form of physical exercise" [OED]. Related: Judoist.
Judy: pet form of Judith. Figurative uses often are from the Punch and Judy puppet show.
jug (n.): "deep vessel for carrying liquids, usually with a handle or ear," late 15c., jugge, variant of jubbe (late 14c.), a word of unknown origin. Perhaps it is from jug "a low woman, a maidservant" (mid-16c.), a familiar alteration of Jug, a common personal name such as Joan or Judith.

Use as a musical instrument is attested from 1886 in jug-band (American English) "musical ensemble in which the bass line is carried or augmented by a player blowing on the open lip of a jug. "As a quantity of ale or beer, a jug is usually a pint" [Century Dictionary, 1902].
jug (interj.): representing the sound of the nightingale, 1530s.
Jugendstil (n.): German equivalent of art nouveau, from "Jugend" ("Youth"), the name of a German magazine begun in 1896 + stil "style." See youth (n.) + style (n.).
juggernaut (n.): "an idea, custom, fashion, etc., that demands either blind devotion or merciless sacrifice," 1854, a figurative use of Juggernaut, 1630s (Iaggernat), "huge wagon bearing an image of the god Krishna," especially that at the town of Puri, drawn annually in procession during which (apocryphally) devotees allowed themselves to be crushed under its wheels in sacrifice. Altered from Jaggernaut, a title of Krishna (an incarnation of Vishnu), from Hindi Jagannath, literally "lord of the world."

This is from Sanskrit jagat "the world, men and beasts" (literally "the moving, all that moves," present participle of *jagati "he goes," from PIE *gwa- "to go, come" (see come (v.)) + natha-s "lord, master," from nathate "he helps, protects," from PIE root *nā- "to help." The first European description of the festival is by Friar Odoric (c. 1321).
juggle (v.): late 14c., jogelen, "entertain by clowning or doing conjuring tricks," back-formation from juggler, and in part from Old French jogler "play tricks, sing songs" (Modern French jongler), from Late Latin ioculare (source of Italian giocolare), from Latin ioculari "to jest" (see jocular).

From c. 1400 as "deceive, put (someone) under a spell." Especially of tricks of manual dexterity and legerdemain from mid-15c. Figurative use, of careers, husbands, etc., is by 1940. Related: Juggled; juggling.
juggler (n.): c. 1100, iugulere "jester, buffoon," also "wizard, sorcerer," from Old English geogelere "magician, conjurer," also from Anglo-French jogelour, Old French jogleor (accusative), from Latin ioculatorem (nominative ioculator) "joker," from ioculari "to joke, to jest" (see jocular). The connecting notion between "magician" and "juggler" is dexterity. Especial sense "one who practices sleight of hand, one who performs tricks of dexterity" is from c. 1600.
jughandle (n.): also jug-handle, "handle of a jug," 1816, from jug (n.) + handle (n.). As a figure of this shape, from 1846. Sense of "tight curved road used for turns" is from 1957.
jughead (n.): "klutz, stupid person," 1926, from jug (n.) + head (n.).