| inspan | v. | [South Africa] to yoke (animals, esp. oxen) to a vehicle; to harness | ||
| inspissated | adj. | thickened, congealed, dried by evaporation; condensed | ||
| instancy | n. | immediateness; urgency, insistent nature | ||
| instant | adj. | of the current calendar month | ||
| instanter | adv. | immediately, right away | ||
| instantiation | n. | representative instance of a more general pattern, algorithm, or concept | ||
| instauration | n. | renewal, restoration; [obsolete] the establishing or instituting (of something) | ||
| insufflate | v. | to blow or breathe into; to introduce air or gas into a body cavity | ||
| intarsia | n. | elaborate Italian form of marquetry; decorative yarnwork using multiple colors of yarn | ||
| integument | n. | covering; natural covering of a body, animal, plant; skin, husk, shell | ||
| intercalary | adj. | inserted, esp. of a day, days, or month inserted into a calendar | ||
| interest | n. | cause or business in which a person has a share | ||
| intermit | v. | to temporarily suspend or discontinue | ||
| internecine | adj. | of or related to fighting within a group; destructive, with great slaughter; mutually destructive | ||
| interstice | n. | small space between things | ||
| intransigent | adj. | irreconcilable, inflexible, uncompromising | ||
| intrant | n. | one who enters, entrant | archaic | |
| intrepid | adj. | dauntless | ||
| introit | n. | psalm read or sung at beginning of the Mass (particularly as the celebrant approaches the Eucharist); introduction | ||
| intumescent | adj. | swollen | ||
| inure | v. | to habituate or to accustom (esp. to hardship, difficulty, pain, etc.) | ||
| invagination | n. | sheathing; intussusception, folding over onto itself | ||
| inveterate | adj. | firmly entrenched through habit or long practice | ||
| invidious | adj. | likely to incite ill will or odium; offensively prejudicial | ||
| invigilate | v. | to watch over students during an exam | ||
| inviolacy | n. | freedom from violation or desecration | ||
| invultuation | n. | creation of an image, esp. a waxen effigy for purposes of witchcraft | ||
| irenic | adj. | non-polemic, pacifying, tending to promote reconciliation | ||
| irid | n. | iris of the eye | ||
| Irish pennant | n. | untidy loose ends of rigging or lines | British | |
| iritis | n. | inflammation of the iris | ||
| ironicon | n. | backwards question mark, intended as a punctuation mark to denote irony; also called a percontation point | ||
| irredentist | adj. | of or related to policy of acquisition by a country of territory belonging to another because of historical or cultural ties; advocate of such policy | ||
| irrefragable | adj. | indisputable, undeniable | ||
| irremissibly | adv. | unforgivably, in a manner precluding all possibility of pardon | ||
| irreprehensible | adj. | blameless, innocent | ||
| irriguous | adj. | well-watered | archaic | |
| isarithm | n. | contour lines | ||
| isochrony | n. | state of occurring at same time or occupying same length of time; theory of linguistic division of time into equal parts | ||
| isogonic | adj. | having equal angles; esp., of lines demarcating points having equal magnetic declination | ||
| isonomy | n. | equality of persons before the law | ||
| ithyphallic | adj. | of the phallus carried in ancient Bacchus festivals; hence, of or pertaining to an erect penis | ||
| jabot | n. | decorative ruffle at neckline descending down the front of the blouse or shirt | ||
| jack-pudding | n. | buffoon, merry-andrew | ||
| Jackson ball | n. | hard penny candy, bull’s eye | obsolete | |
| jade | n. | vicious, worn-out, or worthless horse; disreputable woman | ||
| jagger | n. | pedlar; carrier | ||
| jake leg | n. | paralysis caused by drinking bootleg liquor made from denatured alcohol | ||
| jakes | n. | outhouse | idiom | |
| jankers | n. | punishment detail with pointless tasks, inspections, and confinement to barracks | British |
