| Term | Definition |
| inveterate | deep-rooted; habitual; CF. grow old |
| n invidious | designed to create ill will or envy; tending to rouse ill will or envy; Ex. invidious comparison |
| invincible | unconquerable |
| n inviolable | secure from corruption, attack, or violation(or profanation); unassailable; Ex. inviolable oath/rights; N. inviolability |
| n invocation | prayer for help (used in invoking); calling upon as a reference or support; act of invoking |
| n invoke | call and bring into use (a right or law); call on/upon (a higher power or god) for help; ask for; beg for; conjure (a spirit); Ex. invoke the veto power; Ex. invoke one's advisor/God |
| invulnerable | incapable of injury; impossible to damage or injure |
| iota | very small quantity |
| n irascible | irritable; easily angered |
| n irate | angry; CF. ire: anger; wrath |
| n iridescent | exhibiting rainbowlike colors; Ex. iridescent oil slick; N. iridescence |
| irksome | annoying; tedious; V. irk: annoy |
| ironic | expressing irony; occurring in an unexpected and contrary manner |
| n irony | hidden sarcasm or satire; use of words that seem to mean the opposite of what they actually mean; use of words to convey the opposite of their literal meaning |
| irreconcilable | impossible to reconcile; incompatible; not able to be resolved |
| irrefutable | indisputable; incontrovertible; undeniable |
| irrelevant | not applicable; unrelated |
| irremediable | incurable; uncorrectable; impossible to remedy |
| irreparable | not able to be corrected or repaired; impossible to repair |
| irrepressible | unable to be restrained or held back; impossible to hold back |
| irreproachable | beyond reproach; blameless; impeccable; Ex. irreproachable conduct |
| irresolute | uncertain how to act; weak; lacking in resolution; indecisive; N. irresolution |
| s indecisive | marked by indecision; inconclusive; Ex. indecisive battle |
| s indecision | irresolution; inability to make up one's mind |
| irretrievable | impossible to recover or regain; CF. retrieve |
| irreverence | lack of proper respect or reverence; ADJ. irreverent |
| irrevocable | unalterable; irreversible; impossible to revoke |
| isotope | varying from of an element |
| n isthmus | narrow neck of land connecting two larger bodies of land |
| n itinerant | wandering; traveling from place to place (to perform work); Ex. itinerant preacher |
| n itinerary | plan of a trip; record of a trip |
| n jabber | chatter rapidly or unintelligibly |
| s jab | poke abruptly with something sharp; punch with short blows |
| n jaded | tired or uninterested by surfeit; fatigued; surfeited; worn out; wearied; Ex. jaded appetite |
| jargon | language used by special group; technical terminology; gibberish; nonsensical or incoherent talk |
| n jaundiced | yellowed; prejudiced (envious, hostile, or resentful) from long and disappointing experience of human affairs; Ex. with a jaundiced eye |
| s jaundice | medical condition in which the skin, the white part of the eyes, etc. turn yellow; V: affect with jaundice; affect with prejudice, envy, or hostility; bias |
| n jaunt | trip; short journey |
| n jaunty | cheerful and pleased with life; lighthearted; animated; easy and carefree; dapper in appearance; Ex. jaunty person/hat |
| jeopardize | endanger; imperil; put at risk; N. jeopardy: danger |
| n jettison | throw overboard (from a ship or plane) |
| n jibe | agree; be in harmony with; gibe; to make fun in a tauting way |
| jingoist | extremely aggressive and militant patriot; warlike chauvinist; N. jingoism: extreme nationalism |
| n jocose | given to(having a tendency of) joking |
| n jocular | said or done in jest or playfully; marked by joking |
| s jest | playful remark or act; V. act or speak playfully |
| n jocund | merry |
| n jollity | gaiety; cheerfulness; ADJ. jolly: merry; gay |
| n jostle | shove; bump; push against (someone) rather roughly; Ex. jostled by the crowds |
| s shove | push forward; push roughly; Ex. pushing and shoving to get on the bus; N. |
| s bump | hit or knock against with force; N. |
| n jovial | good-natured; merry; cheerful |
| jubilation | rejoicing; great joy |
| judicious | sound on judgment; wise |
| n juggernaut | irresistible crushing force; overwhelming advancing force that crushes everything in its path |
| s jug | pitcher; container for holding liquids |
| n juncture | crisis; point in time; joining point; joint; act of joining |
| n junket | trip especially one taken for pleasure by an official at public expense |
| n junta | group of persons joined in political intrigue; cabal; group of military officers ruling a country after seizing power (by force) |
| n jurisprudence | science of law |
| s jurisdiction | right and power to apply the law; authority |
| s juridical | of the law and its administration; CF. judicial: of courts of law; CF. judiciary |
| n juxtapose | place side by side; CF. next |
| n kaleidoscope | tube in which patterns made by the reflection in mirrors of colored pieces of glass, etc. produce interesting symmetrical effects; series of changing events; Ex. kaleidoscope of European history; CF. beautiful |
| n ken | range of knowledge; Ex. beyond one's ken |
| kernel | central or vital part; core; whole seed (as of corn) |
| n killjoy | grouch; spoilsport; one who intentionally spoils the pleasure of others |
| s grouch | bad-tempered complaint; person who keeps complaining; V: complain; grumble |
| s spoilsport | one who spoils the pleasure of others |
| kindle | start a fire; ignite; inspire; arouse |
| n kindred | related; belonging to the same group; similar in nature or character; Ex. kindred languages; N: relative; kin; kinship |
| kinetic | producing motion; of motion |
| n kismet | fate; destiny; Ex. Kismet is the Arabic word for fate. |
| n kleptomaniac | person who has a compulsive desire to steal |
| n knave | untrustworthy person; rogue; scoundrel; jack; N. knavery |
| n knead | mix; work dough; mix and work into a uniform mass (with the hands); Ex. knead dough |
| n knell | tolling of a bell especially to indicate a funeral, disaster, etc.; sound of the funeral bell; V. |
| s toll | sound (a large bell) slowly at regular intervals; N: sound of a bell; fixed tax or charge |
| s curfew | regulation requiring all people to leave the streets at stated times; signal (as a bell) announcing the hour of a curfew |
| n knit | contract into wrinkles; grow together; join together closely; make (a fabric or garment) by interwining yarn or thread; Ex. knit the brow; Ex. The bones should knit together in a few weeks. |
| s crochet | make (a piece of needlework) by looping thread with a hooked needle; N. CF. crotchet |
| n knoll | little round hill; hillock |
| n knotty | intricate; difficult; tangled; CF. knot |
| n kudos | honor; glory; acclaim or praise for exceptional achievement |
| s entourage | group of attendants; retinue; CF. surround |
| n labile | likely to change; unstable; Ex. emotionally labile; N. lability |
| laborious | demanding much work or care; tedious |
| labyrinth | maze |
| n laceration | torn ragged wound; V. lacerate: tear (the skin as with broken glass); wound |
| s rip | tear or be torn quickly and violently; Ex. The sail ripped under the force of the wind; N. |
| s rag | scrap of cloth; ADJ. ragged: old and torn; seeming unfinished and imperfect; Ex. ragged debut/performance |
| n lachrymose | producing tears; tearful |
| n lackadaisical | lacking interest or effort; lacking purpose or zest; lazy; halfhearted; languid |
| s halfhearted | exhibiting little interest or enthusiasm |
| n lackluster | lacking luster(shine; gloss); dull |
| n laconic | brief and to the point; using few words; terse |
| n laggard | slow; sluggish; N: one who lags; straggler |