- itemize (v.)
- 1833 (implied in itemized), American English, from item + -ize. Related: Itemizing. An earlier verb was item "make a note of" (c. 1600).
- ivory tower (n.)
- symbol of artistic or intellectual aloofness, by 1889, from French tour d'ivoire, used in 1837 by critic Charles-Augustin Sainte-Beuve (1804-1869) with reference to the poet Alfred de Vigny (1797-1863), whom he accused of excessive aloofness.
Et Vigny, plus secret, comme en sa tour d'ivoire, avant midi rentrait. [Sainte-Beuve, "Pensées d'Août, à M. Villemain," 1837]
Used earlier as a type of a wonder or a symbol of "the ideal." The literal image is perhaps from Song of Solomon [vii:4]:
Thy neck is as a tower of ivory; thine eyes like the fishpools in Heshbon, by the gate of Bathrabbim: thy nose is as the tower of Lebanon which looketh toward Damascus. [KJV]
- itinerate (v.)
- "to travel from place to place," c. 1600, from Late Latin itineratus, past participle of itinerare "to travel" (see itinerant). Especially "to travel from place to place preaching" (1775). Related: Itinerated; itinerating.
- iterative (adj.)
- "involving repetition," late 15c., from French iteratif (c. 1400), from Late Latin iterativus, from iterat-, past participle stem of Latin iterare "do again, repeat" (see iteration). As a noun, "an iterative word," by 1839. Related: Iteratively.
- isomorphic (adj.)
- "the same in form, alike," 1862 [Robert Gordon Latham, "Elements of Comparative Philology"], from iso- "equal, identical" + -morphic, from Greek morphe "form, shape" (see Morpheus). Earlier adjective was isomorphous (1821).
- isomorphism (n.)
- "similarity of form," 1822, in John George Children's translation from French of Berzelius's "The Use of the Blow-pipe in Chemical Analysis," from French l'isomorphisme, from German Isomorphismus (1819), coined by German chemist Eilhard Mitscherlich (1794-1863) from Greek isos "equal, identical" (see iso-) + morphe "form, appearance" (see Morpheus).
Mr. Children has, very properly in our estimation, wholly omitted the formulae, translating them into plain English in notes at the bottom of the page; we wish he had exerted the same discretionary judgment with respect to the isomorphisms and left them out likewise. [from a review of Children's book in "The Quarterly Review of Science, Literature, and the Arts," vol. XIII, 1822]
- isometry (n.)
- in mathematics, 1941, probably from isometric (q.v.) on the model of geometry/geometric.
- isostasy (n.)
- "equilibrium from equality of pressure," 1889 (C.E. Dutton), from iso- + Greek stasis "setting, weighing, standing" (see stasis). Greek isostasios meant "in equipoise with, equivalent to."
- isotherm (n.)
- "line connecting points on the earth having the same mean temperature," 1850, from French isotherme (von Humboldt, 1817), from Greek isos "equal, identical" (see iso-) + therme "heat" (see thermal (adj.)).
- isotonic (adj.)
- "having or indicating equal tones," 1776, from Greek isotonos "of level pitch; equally stretched," from iso- "equal, identical" (see iso-) + tonos "tone" (see tenet).
- isotropic (adj.)
- "having the same properties in all directions," 1856, from iso- + -tropic, from Greek tropikos "belonging to a turning," from tropos "a turning, way, manner," from trepein "to turn" (see trope). Isotropous is from 1859.
- idio-
- word-forming element meaning "one's own, personal, distinct," from Greek idios "own, personal, private, one's own" (see idiom).
- idiotic (adj.)
- 1713, from idiot + -ic or from Late Latin idioticus "uneducated, ignorant," in classical Latin, "of an ordinary person," from Greek idiotikos "unprofessional, unskilled; not done by rules of art, unprofessional," from idiotes "unskilled person" (see idiot). Idiotical is from 1640s. Related: Idiotically.
- idly (adv.)
- Old English idellice "vainly;" see idle + -ly (2). From late 14c. as "in an idle or indolent way."
- idolatrous (adj.)
- 1540s, from idolater + -ous. Related: Idolatrously.
- idolater (n.)
- late 14c., ydolatrer "idol-worshipper," from Old French idolatre, contracted from Late Latin idololatres, from Ecclesiastical Greek eidololatres "idol-worshipper," related to eidolatria (see idolatry).
- ignition (n.)
- 1610s, "act of heating to the point of combustion," from French ignition or directly from Medieval Latin ignitionem (nominative ignitio), noun of action from past participle stem of Latin ignire "set on fire," from ignis "fire" (see igneous). Meaning "means of sparking a fire" (originally in a gun) is from 1881; meaning "means of sparking an internal combustion engine" is from 1906.
- ileum (n.)
- lowest part of the small intestine, 1680s, medical Latin, from ileum, in medieval medicine "the part of the small intestines in the region of the flank," singular created from Latin ilia (pl.) "groin, flank," in classical Latin, "belly, the abdomen below the ribs," poetically, "entrails, guts." The word apparently was confused in Latin with Greek eileos "colic" (see ileus), or perhaps is a borrowing of it. The sense is "winding, turning," either via the Greek meaning or from the convolutions of the intestines. Earlier in English ylioun (late 14c.), from Medieval Latin ileon. Related: Ileitis; ileal.
- ilium (n.)
- pelvic bone, 1706, Modern Latin, from Latin ilia (plural) "groin, flank, side of the body from the hips to the groin" (see ileum). In Middle English it meant "lower part of the small intestine." Vesalius gave the name os ilium to the "bone of the flank."
- illustrative (adj.)
- 1640s, from illustrat-, past participle stem of Latin illustrare (see illustration) + -ive.
- illustrator (n.)
- 1590s, "one who enlightens," agent noun in Latin form from illustrate, or from Late Latin illustrator "an enlightener." Meaning "one who draws pictures" is 1680s.
- imaginary (adj.)
- "not real, existing only in fancy," late 14c., ymaginaire, from imagine + -ary; or else from Late Latin imaginarius "seeming, fancied," also literal, "pertaining to an image," from Latin imaginari "picture to oneself." Imaginary friend (one who does not exist) attested by 1789.
- imagination (n.)
- "faculty of the mind which forms and manipulates images," mid-14c., ymaginacion, from Old French imaginacion "concept, mental picture; hallucination," from Latin imaginationem (nominative imaginatio) "imagination, a fancy," noun of action from past participle stem of imaginari (see imagine).
- imaginative (adj.)
- late 14c., ymaginatyf, "pertaining to imagination; forming images, given to imagining," from Old French imaginatif and directly from Medieval Latin imaginativus, from imaginat-, stem of Latin imaginari "picture to oneself" (see imagine). Meaning "resulting from imagination" is from 1829. Related: Imaginatively; imaginativeness.
- imaginable (adj.)
- late 14c., ymaginable, from Old French imaginable and directly from Late Latin imaginabilis, from Latin imaginari "picture to oneself" (see imagine). Related: Imaginably.
- imitate (v.)
- 1530s, a back-formation from imitation or imitator, or else from Latin imitatus, past participle of imitari "to copy, portray." Related: Imitated; imitating. An Old English word for this was æfterhyrigan.
- imitative (adj.)
- 1580s, probably from imitate + -ive; or else from Middle French imitatif, from Late Latin imitativus, from imitat-, stem of Latin imitari "to copy, portray" (see imitation).
- imitator (n.)
- 1520s, from Middle French imitateur (14c.) or directly from Latin imitator "a copyist; a mimic," from imitari "to copy, imitate" (see imitation).
- immaturity (n.)
- 1530s, "untimeliness," from Latin immaturitatem (nominative immaturitas) "unripeness," from immaturus "unripe, untimely" (see immature). Meaning "lack of maturity" attested from c. 1600.
- immediacy (n.)
- c. 1600, from immediate + -cy. Middle English had immediacioun "close connection, proximity" (mid-15c.).
- immerse (v.)
- "to plunge into (a fluid)," early 15c. (implied in immersed), from Latin immersus, past participle of immergere "to plunge in, dip into, sink, submerge" (see immersion). Figuratively, of study, work, passion, etc., from 1660s. Related: Immersed; immersing; immersive.
- imminence (n.)
- c. 1600, from Late Latin imminentia, from Latin imminentem (see imminent).
- immobile (adj.)
- mid-14c., originally of property; by c. 1400 "steadfast, unmovable" (of faith, etc.), from Old French immoble "immovable, fixed, motionless" (13c., Modern French immeuble), from Latin immobilis "immovable" (also, figuratively, "hard-hearted"), from assimilated form of in- "not, opposite of" (see in- (1)) + mobilis (see mobile (adj.)). Related: Immobilism "policy of extreme conservatism" (1853).
- immobilize (v.)
- "render immobile," 1843, from immobile + -ize. Perhaps modeled on French immobiliser (1835). Related: Immobilized; immobilizing.
- immoderate (adj.)
- "excessive, extreme, lacking moderation," late 14c., from Latin immoderatus "boundless, immeasurable," figuratively "unrestrained, excessive," from assimilated form of in- "not, opposite of" (see in- (1)) + moderatus "restrained" (see moderate (adj.)). Related: Immoderately.
- immolation (n.)
- early 15c., "a sacrificing, sacrificial killing" (originally especially with reference to Christ), from Old French immolacion "offering, sacrifice" (13c.) or directly from Latin immolationem (nominative immolatio) "a sacrificing," noun of action from past participle stem of immolare "to sacrifice" (see immolate).
- immorality (n.)
- 1560s, from assimilated form of in- (1) "not, opposite of" + morality.
- immortality (n.)
- mid-14c., "deathlessness," from Old French immortalité (13c.) and directly from Latin immortalitatem (nominative immortalitas) "deathlessness, endless life," also "imperishable fame," from immortalis "undying" (see immortal). Of fame, etc., "quality of being permanent," early 15c.
- immortalize (v.)
- 1560s, "bestow lasting fame upon, exempt from oblivion," from immortal + -ize. Perhaps modeled on Middle French immortaliser. The literal sense "endow with immortality" is from 1630s in English. Related: Immortalized; immortalizing.
- immune (adj.)
- mid-15c., "free, exempt" (from taxes, tithes, sin, etc.), from Latin immunis "exempt from public service, untaxed; unburdened, not tributary," from assimilated form of in- "not, opposite of" (see in- (1)) + munis "performing services" (compare municipal), from PIE *moi-n-es-, suffixed form of root *mei- (1) "to change" (see mutable). Specific modern medical sense of "exempt (from a disease)," typically because of inoculation, is from 1881, a back-formation from immunity. Immune system attested by 1917.
- immovable (adj.)
- late 14c., literal and figurative, also sometimes in Middle English immevable, from assimilated form of in- (1) "not, opposite of" + movable. Related: Immovably.
- immunization (n.)
- 1892, noun of action from immunize.
- immunize (v.)
- 1889, in a translation of a German article, from immune + -ize. Related: Immunized; immunizing.
- impact (n.)
- 1738, "collision, act of striking against, striking of one thing against another," from impact (v.). Figurative sense of "forceful impression" is from 1817 (Coleridge).
- impassion (v.)
- 1590s, "inflame with passion," from Italian impassionare "to fill with passion," from assimilated form of in- "in, into" (see in- (2)) + passione "passion," from Latin passionem (see passion). Related: Impassioned; impassionable. Formerly also empassion.
- impatience (n.)
- "restlessness under existing conditions," c. 1200, from Old French impacience "impatience" (12c., Modern French impatience) and directly from Latin impatientia "impatience; weakness," from impatiens "intolerant, impatient" (see impatient).
- impeachment (n.)
- late 14c., enpechement "accusation, charge," from Old French empeechement "difficulty, hindrance; (legal) impeachment," from empeechier "to hinder, impede" (see impeach). As a judicial proceeding on charges of maladministration against a public official, from 1640s.
- impeller (n.)
- 1680s, agent noun from impel (v.). As a machine part from 1836.
- impenetrable (adj.)
- mid-15c., from Middle French impenetrable (14c.) or directly from Latin impenetrabilis "that cannot be penetrated," from assimilated form of in- "not, opposite of" (see in- (1)) + penetrabilis "penetrable" (see penetrable). Related: Impenetrably; impenetrability.
- imperfection (n.)
- late 14c., "incompleteness, deficiency, lack," from Old French imperfeccion "defect; imperfect state" (12c.) and directly from Late Latin imperfectionem (nominative imperfectio) "imperfection," noun of action from Latin imperfectus "imperfect"(see imperfect). Meaning "an instance of being imperfect" is from early 15c.