idiomatic (adj.) Look up idiomatic at
1712, from Latin idiomaticus, from Greek idiomatikos; from idios "one's own" (see idiom) + matos "thinking, animated" (see automaton).
idiopathy (n.) Look up idiopathy at
1640s, Modern Latin, from Greek idiopatheia, from comb. form of idios "one's own" (see idiom) + -patheia, comb. form of pathos "suffering, disease, feeling" (see pathos). Related: idiopathic.
idiosyncrasy (n.) Look up idiosyncrasy at
c. 1600, from French idiosyncrasie, from Greek idiosynkrasia "a peculiar temperament," from idios "one's own" (see idiom) + synkrasis "temperament, mixture of personal characteristics," from syn "together" (see syn-) + krasis "mixture" (see rare (adj.2)). Originally in English a medical term meaning "physical constitution of an individual." Mental sense first attested 1660s.
idiosyncratic (n.) Look up idiosyncratic at
1779, from idiosyncrasy + -ic. Earlier in same sense was idiosyncratical (1640s). Related: Idiosyncratically.
idiot (n.) Look up idiot at
early 14c., "person so mentally deficient as to be incapable of ordinary reasoning;" also in Middle English "simple man, uneducated person, layman" (late 14c.), from Old French idiote "uneducated or ignorant person" (12c.), from Latin idiota "ordinary person, layman; outsider," in Late Latin "uneducated or ignorant person," from Greek idiotes "layman, person lacking professional skill" (opposed to writer, soldier, skilled workman), literally "private person (as opposed to one taking part in public affairs)," used patronizingly for "ignorant person," from idios "one's own" (see idiom).
Reader, suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself. [Mark Twain, c. 1882]
Idiot box "television set" is from 1959; idiot light "dashboard warning signal" is attested from 1968. Idiot savant attested by 1870.
idiotic (adj.) Look up idiotic at
1713, 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 (see idiot). Idiotical is from 1640s. Related: Idiotically.
idle (adj.) Look up idle at
Old English idel "empty, void; vain; worthless, useless; not employed," common West Germanic (cognates: Old Saxon idal, Old Frisian idel "empty, worthless," Old Dutch idil, Old High German ital, German eitel "vain, useless, mere, pure"), of unknown origin. Idle threats preserves original sense; meaning "lazy" is c. 1300.
idle (v.) Look up idle at
late 15c., "make vain or worthless," from idle (adj.). Meaning "spend or waste (time)" is from 1650s. Meaning "cause to be idle" is from 1789. Sense of "running slowly and steadily without transmitting power" (as a motor) first recorded 1916. Related: Idled; idling.
idleness (n.) Look up idleness at
Old English idelnes "frivolity, vanity, emptiness; vain existence;" see idle + -ness. Old English expressed the idea we attach to in vain by in idelnisse. Spenser, Scott, and others use idlesse to mean the same thing in a positive, pleasant sense.
idler (n.) Look up idler at
1530s, agent noun from idle.
idly (adv.) Look up idly at
Old English idellice; see idle + -ly (2).
Ido Look up Ido at
1908, artificial language based on Esperanto, devised 1907; from Ido -ido “offspring,” suffix representing Latin -ida, Greek -ides.
idol (n.) Look up idol at
mid-13c., "image of a deity as an object of (pagan) worship," from Old French idole "idol, graven image, pagan god," from Late Latin idolum "image (mental or physical), form," used in Church Latin for "false god," from Greek eidolon "appearance, reflection in water or a mirror," later "mental image, apparition, phantom," also "material image, statue," from eidos "form" (see -oid). Figurative sense of "something idolized" is first recorded 1560s (in Middle English the figurative sense was "someone who is false or untrustworthy"). Meaning "a person so adored" is from 1590s.
idolater (n.) Look up idolater at
late 14c., ydolatrer "idol-worshipper," from Old French idolatre, contracted from Late Latin idololatres, from Ecclesiastical Greek eidololatres "idol-worshipper" (see idolatry).
idolatrous (adj.) Look up idolatrous at
1540s, from idolater + -ous.
idolatry (n.) Look up idolatry at
mid-13c., from Old French idolatrie, from Vulgar Latin idolatria, shortened from Late Latin idololatria (Tertullian), from Ecclesiastical Greek eidololatria "worship of idols," from eidolon "image" (see idol) + latreia "worship, service" (see -latry).
idolize (v.) Look up idolize at
1590s, from idol + -ize. Related: Idolized; idolizing.
idyll (n.) Look up idyll at
also idyl, c. 1600, "picturesque pastoral poem," from Latin idyllium, from Greek eidyllion "short, descriptive poem, usually of rustic or pastoral type," literally "a little picture," diminutive of eidos "form" (see -oid).
idyllic (adj.) Look up idyllic at
"full of natural, simple charm," 1831, literally "suitable for an idyll" (late 18c. in sense "pertaining to an idyll"); from idyll + -ic.
if (conj.) Look up if at
Old English gif (initial g- in Old English pronounced with a sound close to Modern English -y-), from Proto-Germanic *ja-ba (cognates: Old Saxon, Old Norse ef, Old Frisian gef, Old High German ibu, German ob, Dutch of "if, whether"), from PIE pronominal stem *i- [Watkins]; Klein, OED suggest probably originally from an oblique case of a noun meaning "doubt" (compare Old High German iba "condition, stipulation, doubt," Old Norse if "doubt, hesitation," Swedish jäf "exception, challenge"). As a noun from 1510s.
iffy (adj.) Look up iffy at
1937, American English, from if + -y (2). Originally associated with President Franklin D. Roosevelt.
igloo (n.) Look up igloo at
1824, Canadian English, from an Eskimo word for "house, dwelling" (compare Greenlandic igdlo "house").
Ignatius Look up Ignatius at
masc. proper name, from Latin Ignatius, collateral form of Egnatius.
igneous (adj.) Look up igneous at
1660s, from Latin igneus "of fire, fiery," from ignis "fire," from PIE *egni- "fire" (cognates: Sanskrit agnih "fire, sacrificial fire," Old Church Slavonic ogni, Lithuanian ugnis "fire").
ignis fatuus (n.) Look up ignis fatuus at
"will o' the wisp, jack-a-lantern," 1560s, from Medieval Latin, literally "foolish fire;" see igneous + fatuous.
ignitable (adj.) Look up ignitable at
1640s; see ignite + -able.
ignite (v.) Look up ignite at
1660s, from Latin ignitus, past participle of ignire "set on fire," from ignis "fire" (see igneous). Attested earlier as an adjective (1550s). Related: Ignited; igniting.
ignition (n.) Look up ignition at
1610s, "act of heating to the point of combustion," from French ignition (16c.) or directly from Medieval Latin ignitionem (nominative ignitio), from Latin ignire "set on fire," from ignis "fire" (see igneous). Meaning "means of sparking an internal combustion engine" is from 1881.
ignivomous (adj.) Look up ignivomous at
"vomiting fire," c. 1600, from Late Latin ignivomous, from Latin ignis "fire" (see igneous) + vomere "to vomit" (see vomit).
ignoble (adj.) Look up ignoble at
mid-15c., "of low birth," from Middle French ignoble, from Latin ignobilis "unknown, undistinguished, obscure; of base birth, not noble," from assimilated form of in- "not, opposite of" (see in- (1)) + gnobilis "well-known, famous, renowned, of superior birth" (see noble). Related: Ignobly.
ignominious (adj.) Look up ignominious at
early 15c., from Middle French ignominieux (14c.) or directly from Latin ignominiosus "disgraceful, shameful," from ignominia "loss of a (good) name," from assimilated form of in- "not, opposite of" (see in- (1)) + nomen (genitive nominis) "name" (see name). Influenced by Old Latin gnoscere "come to know." Related: Ignominiously; ignominiousness.
ignominy (n.) Look up ignominy at
1530s, back-formation from ignominious or else from Middle French ignominie (15c.), from Latin ignominia "disgrace, dishonor" (see ignominious). Also sometimes shortened to ignomy.
ignoramus (n.) Look up ignoramus at
1570s, from an Anglo-French legal term (early 15c.), from Latin ignoramus "we do not know," first person present indicative of ignorare "not to know" (see ignorant). The legal term was one a grand jury could write on a bill when it considered the prosecution's evidence insufficient. Sense of "ignorant person" came from the title role of George Ruggle's 1615 play satirizing the ignorance of common lawyers.
ignorance (n.) Look up ignorance at
c. 1200, from Old French ignorance (12c.), from Latin ignorantia "want of knowledge" (see ignorant).
ignorant (adj.) Look up ignorant at
late 14c., from Old French ignorant (14c.), from Latin ignorantia, from ignorantem (nominative ignorans), present participle of ignorare "not to know, to be unacquainted; mistake, misunderstand; take no notice of, pay no attention to," from assimilated form of in- "not, opposite of" (see in- (1)) + Old Latin gnarus "aware, acquainted with" (cognates: Classical Latin noscere "to know," notus "known"), from Proto-Latin suffixed form *gno-ro-, related to gnoscere "to know" (see know).

Form influenced by Latin ignotus "unknown." Also see uncouth. Colloquial sense of "ill-mannered" first attested 1886. As a noun meaning "ignorant person" from mid-15c.
ignore (v.) Look up ignore at
1610s, "not to know, to be ignorant of," from French ignorer "be unaware of," from Latin ignorare "not to know, disregard" (see ignorant). Sense of "pay no attention to" first recorded 1801 (Barnhart says "probably a dictionary word"), and not common until c. 1850. Related: Ignored; ignoring.
iguana (n.) Look up iguana at
1550s, from Spanish, from Arawakan (W.Indies) iguana, iwana, the local name for the lizard.
Foure footed beastes ... named Iuannas, muche lyke vnto Crocodiles, of eyght foote length, of moste pleasaunte taste. [Richard Eden, "Decades of the New World," 1555]
Iguanodon (n.) Look up Iguanodon at
dinosaur name, 1825, hybrid from iguana + stem of Greek odonys "tooth" (on model of mastodon). So called because the fossil teeth and bones were thought to resemble those of the lizard.
ikebana (n.) Look up ikebana at
1901, from Japanese, from ikeru "to keep alive, arrange" + hana "flower."
il- Look up il- at
assimilated form of Latin prefix in- used with words beginning in l-; see in-.
ileo- Look up ileo- at
comb. form from ileum (q.v.).
ileum (n.) Look up ileum at
lowest part of the small intestine, 1680s, medical Latin, from ileum, singular created from classical Latin plural ilia "groin, flank," in classical Latin, "belly, the abdomen below the ribs," poetically, "entrails, guts." Sense restriction and form apparently from confusion with Greek eileos (see ileus). Earlier in English ylioun (late 14c.), from Medieval Latin ileon. Related: Ileitis.
ileus (n.) Look up ileus at
painful intestinal condition, 1706, from Latin ileus "severe colic," from Greek ileos "colic," from eilein "to turn, squeeze," from PIE *wel- (3) "to turn, roll" (see volvox).
ilex (n.) Look up ilex at
late 14c., from Latin ilex "holm-oak," perhaps from an extinct non-Indo-European language.
ilia Look up ilia at
Latin plural of ilium (see ileum).
iliac (adj.) Look up iliac at
1510s, "pertaining to the disease ileus or colic," from French iliaque or directly from Late Latin iliacus, from ilium "flank, side, entrails" (see ileum).
Iliad Look up Iliad at
from Latin Ilias (genitive Iliadis), from Greek Ilias poiesis "poem of Ilion" (Troy), literally "city of Ilius," the mythical founder.
ilium (n.) Look up ilium at
pelvic bone, 1706, Modern Latin, from Latin ilia (plural) "groin, flank" (see ileum).
ilk (adj.) Look up ilk at
Old English ilca "same" (n. and adj.), from Proto-Germanic *ij-lik, in which the first element is from the PIE demonstrative particle *i- (see yon) and the second is that in Old English -lic "form" (see like). Of similar formation are which and such. Phrase of that ilk implies coincidence of name and estate, as in Lundie of Lundie; applied usually to families, so by c. 1790 it began to be used with meaning "family," then broadening to "type, sort."
ill (adj.) Look up ill at
c. 1200, "morally evil" (other 13c. senses were "malevolent, hurtful, unfortunate, difficult"), from Old Norse illr "ill, bad," of unknown origin. Not considered to be related to evil. Main modern sense of "sick, unhealthy, unwell" is first recorded mid-15c., probably related to Old Norse idiom "it is bad to me." Slang inverted sense of "very good, cool" is 1980s. As a noun, "something evil," from mid-13c.