| jarvey | n. | hackney coachman | ||
| jauk | v. | to dawdle | Scots | |
| javelina | n. | collared peccary | ||
| jeepney | n. | two-bench jitney bus, usually with bright-colored and garish designs, commonly used throughout the Philippines | ||
| jehu | n. | fast driver, often furiously so; cabman | colloquial | |
| jejune | adj. | boring, uninteresting; lacking content or matter or nutritive substance; immature, juvenile | ||
| jeofail | n. | mistake in legal pleading; acknowledgement of such mistake | ||
| jess | n. | short leather strap tied around each leg of a hunting hawk, usu. with ring for attaching bird to its perch | ||
| jessie | n. | sissy, coward, effeminate boy or man | slang | |
| jetton | n. | token or counter of metal, etc. | ||
| jiggery-pokery | n. | trickery; manipulation | British | |
| jillflirt | n. | wanton, giddy young girl | archaic | |
| jingo | n. | bellicose patriot | ||
| jink | v. | to move jerkily; to elude | ||
| jipijapa | n. | Panama hat | ||
| jobsworth | n. | worker or official using their petty authority unhelpfully and refusing to make accommodations for particular cases | British | |
| jockey box | n. | insulated container using ice, water, and coils to provide cold beverages at at temporary location; container on conveyance for tools, etc. | ||
| jocund | adj. | merry, cheerful, blithe | ||
| jodhpurs | n. | riding pants cut very loosely over the hips and thighs with a tight fit from the calf to the ankle | ||
| jorum | n. | large drinking-bowl | ||
| joss | n. | Chinese cult image or idol | ||
| journal box | n. | metal box on side frame of railroad truck containing bearings and one end of an axle | ||
| judder | v. | to violently shake | ||
| juggins | n. | fool, simpleton | British | |
| junket | n. | cream cheese, or food made from sweet curds; pleasure trip, usu. one ostensibly for business purposes | ||
| jupon | n. | short, sleeveless tunic worn over armor | ||
| justle | v. | variant of jostle | ||
| kaddish | n. | prayer sequence in the Jewish faith; prayers for the dead | ||
| kakistocracy | n. | government by the worst citizens | ||
| kalpak | n. | high-crowned hat of Turkic peoples | ||
| kalsomine | n. | calcimine, whitewash | ||
| katagelasticism | n. | joy at laughing at others without compunction | ||
| kedge | v. | to warp a ship or boat by hauling on a cable attached to an anchor dropped at some distance from the vessel | ||
| kedgeree | n. | Indian dish of rice, onion, lentils, and spices; European dish of rice, fish, eggs | ||
| Keeley Cure | n. | supposed cure for alcoholism of the Keeley Institute at the cusp of the 20th Century, primarily consisting of injections of auric chloride | ||
| keep chup | v. | to keep quiet, to stay silent | ||
| kegling | n. | bowling | ||
| keimelia | n. | stored up or hidden treasure | ||
| kelson | n. | timber lined alongside the keel on floor-timbers of a ship, attaching the one to the other (also keelson) | ||
| kempt | adj. | neat, well maintained; combed | ||
| keratolysis | n. | shedding of the epidermis, esp. its horny layers | ||
| keratometer | n. | device used for measuring curvature of cornea, principally to assess astigmatism | ||
| kerf | n. | cut made by a saw | ||
| kermis | n. | fair or festival | ||
| kettle | v. | to confine to a small area as means of crowd control | British | |
| keystone | v. | to project an image improperly so that the projecting plane is not aligned with the receiving surface and thus causing distortion | ||
| kindle | n. | litter of kittens, rabbits, etc. | ||
| kipple | n. | useless detritus that seems to reproduce when nobody is present (coined by Philip K. Dick) | ||
| kirmess | n. | street fair in Dutch or German lands; indoor fair, often for charitable purpose | ||
| kirtle | n. | long women’s garment worn from medieval times to the Baroque Era over smock or chemise |
