Jupiter (n.)
c.1200, "supreme deity of the ancient Romans," from Latin Iupeter, from PIE *dyeu-peter- "god-father" (originally vocative, "the name naturally occurring most frequently in invocations" [Tucker]), from *deiw-os "god" (see Zeus) + peter "father" in the sense of "male head of a household" (see father). Compare Greek Zeu pater, vocative of Zeus pater "Father Zeus;" Sanskrit Dyauspita "heavenly father." The planet name is attested from late 13c. Jupiter Pluvius "Jupiter as dispenser of rain" was used jocularly from 1864.
Jurassic (adj.)
in reference to "geological period between the Triassic and the Cretaceous," 1847, from French Jurassique, literally "of the Jura Mountains," between France and Switzerland, whose limestones were laid down during this geological period. Used in English in a literal sense "pertaining to the Jura Mountains" by 1831. The name is said to be from Gaulish *iuris "wooded mountain."
jurat (n.)
"one who has taken an oath," early 15c. (mid-14c. in Anglo-French), from Medieval Latin iuratus, literally "sworn man," noun use of past participle of iurare "to swear" (see jury (n.)).
juridical (adj.)
c.1500, from Latin iuridicalis "relating to right; pertaining to justice," from iuridicus, from ius "right, law" (genitive iuris; see jurist) + dicere "to say, to speak" (see diction). Related: Juridically.
jurisdiction (n.)
early 14c. "administration of justice" (attested from mid-13c. in Anglo-Latin), from Old French juridiccion (13c.) and directly from Latin iurisdictionem (nominative iurisdictio) "administration of justice, jurisdiction," from ius (genitive iuris; see jurist) "right, law" + dictio "a saying" (see diction). Meaning "extent or range of administrative power" is from late 14c. Related: Jurisdictional.
jurisprudence (n.)
1620s, "knowledge of law," from French jurisprudence (17c.) and directly from Late Latin iurisprudentia "the science of law," from iuris "of right, of law" (genitive of ius; see jurist) + prudentia "knowledge, a foreseeing" (see prudence). Meaning "the philosophy of law" is first attested 1756. Related: Jurisprudential.
jurist (n.)
mid-15c., "one who practices law," from Middle French juriste (14c.), from Medieval Latin iurista "jurist," from Latin ius (genitive iuris) "law," from PIE *yewes- "law," originally a term of religious cult, perhaps meaning "sacred formula" (compare Latin iurare "to pronounce a ritual formula," Vedic yos "health," Avestan yaoz-da- "make ritually pure," Irish huisse "just").

The Germanic root represented by Old English æ "custom, law," Old High German ewa, German Ehe "marriage," though sometimes associated with this group, seems rather to belong to PIE *ei- "to go." Meaning "a legal writer" is from 1620s.
juror (n.)
c.1300 (attested from late 12c. in Anglo-Latin), from Anglo-French jurour (late 13c.; Old French jureor), from Latin iuratorem (nominative iurator) "swearer," agent noun from iurare "to swear" (see jury (n.)).
jury (n.)
early 14c. (attested from late 12c. in Anglo-Latin), from Anglo-French juree (late 13c.), from Medieval Latin iurata "an oath, an inquest," fem. past participle of Latin iurare "to swear," from ius (genitive iuris) "law" (see jurist). Meaning "body of persons chosen to award prizes at an exhibition" is from 1851. Grand jury attested from early 15c. in Anglo-French (le graund Jurre).
jury (adj.)
"temporary," 1610s, in jury-mast, a nautical term for a temporary mast put in place of one broken or blown away, of uncertain origin. The word perhaps is ultimately from Old French ajurie "help, relief," from Latin adjutare (see aid (n.)).
jus
French, literally "juice" (see juice).
jussive
"grammatical mode expressing command," 1846, from Latin iuss-, past participle stem of iubere "to bid, command," from PIE *yeudh- "to move violently, fight;" + -ive.
just (adj.)
late 14c., "righteous in the eyes of God; upright, equitable, impartial; justifiable, reasonable," from Old French juste "just, righteous; sincere" (12c.), from Latin iustus "upright, equitable," from ius "right," especially "legal right, law," from Old Latin ious, perhaps literally "sacred formula," a word peculiar to Latin (not general Italic) that originated in the religious cults, from PIE root *yewes- "law" (cognates: Avestan yaozda- "make ritually pure;" see jurist). The more mundane Latin law-word lex covered specific laws as opposed to the body of laws. The noun meaning "righteous person or persons" is from late 14c.
just (adv.)
"merely, barely," 1660s, from Middle English sense of "exactly, precisely, punctually" (c.1400), from just (adj.), and paralleling the adverbial use of French juste. Just-so story first attested 1902 in Kipling, from the expression just so "exactly that, in that very way" (1751).
justice (n.)
mid-12c., "the exercise of authority in vindication of right by assigning reward or punishment;" also "quality of being fair and just," from Old French justice "justice, legal rights, jurisdiction" (11c.), from Latin iustitia "righteousness, equity," from iustus "upright, just" (see just (adj.)). The Old French word had widespread senses, including "uprightness, equity, vindication of right, court of justice, judge." The word began to be used in English c.1200 as a title for a judicial officer. Meaning "right order, equity" is late 14c. Justice of the peace first attested early 14c. In the Mercian hymns, Latin iustitia is glossed by Old English rehtwisnisse. To do justice to (someone or something) "render fully and fairly showing due appreciation" is from 1670s.
justiciable (adj.)
mid-15c., from Old French justisable "amenable to a jurisdiction," from justicier, from Latin iustitia (see justice).
justifiability (n.)
1835, from justifiable + -ity.
justifiable (adj.)
1520s, from Old French justifiable, from justifiier (see justify). Earlier in same sense was justificable (mid-15c.). Related: Justifiably (mid-15c.).
justification (n.)
late 14c., "administration of justice," from Late Latin iustificationem (nominative iustificatio), noun of action from past participle stem of iustificare (see justify). Meaning "action of justifying" is from late 15c. Theological sense is from 1520s.
justified (adj.)
1580s, "made right," past participle adjective from justify. Typesetting sense is from 1670s.
justify (v.)
c.1300, "to administer justice;" late 14c., "to show (something) to be just or right," from Old French justifiier "submit to court proceedings" (12c.), from Latin iustificare "act justly toward, make just," from iustificus "dealing justly, righteous," from iustus "just" (see just (adj.)) + root of facere "to do" (see factitious). Of circumstances, "to afford justification," from 1630s. Meaning "to make exact" (now largely restricted to typesetting) is from 1550s. Related: Justified; justifying.
Justin
masc. proper name, from Latin Iustinus, literally "just," from iustus (see just (adj.)).
Justine
fem. proper name, fem. of Latin Iustinus (see Justin).
justly (adv.)
early 14c., "in an adjacent position, closely," from just (adj.) + -ly (2). Meanings "truthfully, honestly," "in an equitable manner, with justice, fairly" are from late 14c. Sense of "justifiably, with good reason" is from c.1400; that of "legally, legitimately, rightfully" is early 15c.
justness (n.)
early 15c., from just (adj.) + -ness.
jut (v.1)
"to protrude," mid-15c., corruption of obsolete jet (see jetty). Related: Jutted; jutting.
jut (v.2)
"to strike, hit, push," 1540s, echoic. Related: Jutted; jutting.
jute (n.)
plant fiber, 1746, from Bengali jhuto, from Sanskrit juta-s "twisted hair," related to jata "braid of hair," of unknown origin, probably from a non-Indo-European language.
Jute
Old English Eotas, one of the ancient Germanic inhabitants of Jutland in Denmark; traditionally they were said to have settled in Kent and Hampshire during the 5c. invasion of Britain. The name is related to Old Norse Iotar.
juvenal
1580s (n.), 1630s (adj.), from Latin iuvenalis "of or belonging to youth," from iuvenis "a young person" (see young). The Roman satirist is Decimius Junius Juvenalis.
juvenescence (n.)
1800; see juvenescent + -ence.
juvenescent (adj.)
1821, from Latin iuvenescentem (nominative iuvenescens), present participle of iuvenescere "to grow into youth," from iuvenis "young" (see young).
juvenile (adj.)
1620s, from Latin iuvenilis "of or belonging to youth," from iuvenis "young person," originally "young" (compare French jeune; see young). Juvenile delinquency first recorded 1816; Juvenile delinquent the following year.
juvenilia (n.)
"works of a person's youth," 1620s, from Latin iuvenilia, neuter plural of iuvenilis (see juvenile).
juvenility (n.)
1620s, from Latin iuvenilitas "youth," from iuvenilis (see juvenile).
Juventus
Roman god of youth, personification of iuventas "youth," from iuvenis "a young person" (see young).
juxtapose (v.)
1851, from French juxtaposer (1835), from Latin iuxta (see juxtaposition) + French poser (see pose (v.1)). Related: Juxtaposed; juxtaposing.
juxtaposition (n.)
1660s, from French juxtaposition (1660s), from Latin iuxta "beside, near" + French position (see position (n.)). Latin iuxta is a contraction of *iugista (adv.), superlative of adjective *iugos "closely connected," from stem of iugum "yoke," from iungere "to join" (see jugular).
jynx (n.)
"wryneck," 1640s, from Modern Latin jynx (plural jynges), from Latin iynx (see jinx).