Online Etymology Dictionary

kasbah (n.): see casbah.
Kashmir: from Sanskrit Kashypamara "land of Kashyap," said to be the name of a renowned sage. Related: Kashmiri.
katakana (n.): from Japanese katakana, from kata "side" + kana "borrowed letter(s)."
katana (n.): 1610s, from Japanese.
Kate: fem. proper name, pet form of Katherine. In World War II it was the Allies' nickname for the standard torpedo bomber used by the Imperial Japanese Navy.
kathenotheism (n.): "a form of polytheism characteristic of the Vedic religion, in which one god at a time is considered supreme," 1865, coined in German by Max Müller from Greek kath' hena "one by one" + theism. Müller also coined henotheism (1860), from Greek henos "one," for "faith in a single god" as distinguished from exclusive belief in only one god, in writings on early Hebrew religion.
Katherine: fem. proper name, also Katharine, see Catherine.
Kathmandu: Nepalese capital, from Nepalese Kathmandu, from kath "wooden" + mandu "temple."
Katie: diminutive form of Kate.
katydid (n.): insect of the locust family (Microsentrum rhombifolium), 1784, American English (perhaps first used by John Bartram), imitative of the stridulous sound the male makes when it rubs its front wings together. The sound itself is more accurately transcribed from 1751 as catedidist.
katzenjammer (n.): 1849, "a hangover," American English colloquial, from German katzen, comb. form of katze "cat" + jammer "distress, wailing." Hence, "any unpleasant reaction" (1897).
Pleasure can intoxicate, passion can inebriate, success can make you quite as drunk as champagne. The waking from these several stages of delights will bring the same result--Katzenjammer. In English you would call it reaction; but whole pages of English cannot express the sick, empty, weary, vacant feeling which is so concisely contained within these four German syllables. ["Blackwood's Edinburgh Magazine," August 1884]
Katzenjammer Kids "spectacularly naughty children" is from title of comic strip first drawn by German-born U.S. comic strip artist Rudolph Dirks (1877-1968) in 1897 for the "New York Journal."
"THE SHENANIGAN KIDS" is the new American name for the original "Katzenjammer Kids." Although the original name and idea were pure Holland Dutch, some people may have had the mistaken impression that they were of Germanic origin, and hence the change. It is the same splendid comic as in the past. [International Feature Service advertisement in "Editor & Publisher," July 6, 1918]
Kay: fem. proper name, often a shortening of Katherine. As a given name for girls, from 1890s in the U.S.; in the top 100 for girls born there 1936-1945.
kayak (n.): 1757, from Danish kajak, from Greenland Eskimo qayaq, literally "small boat of skins." The verb is attested from 1875, from the noun.
Kayla: fem. proper name, extended form of Kay. Rare before 1962; a top-20 name for girls born in the U.S. 1988-2004.
kayo: spelled-out form of K.O. (knockout), from 1923. Also used in 1920s as a slang reversal of OK.
Kazakhstan: from the indigenous Kazakh people (from the Turkish root kazak "nomad;" see Cossack) + Iranian root -stan "country, land" (see -stan).
kazoo (n.): 1884, American English, probably altered from earlier bazoo "trumpet" (1877); probably ultimately imitative (cf. bazooka). In England, formerly called a Timmy Talker, in France, a mirliton.
Kazoos, the great musical wonder, ... anyone can play it; imitates fowls, animals, bagpipes, etc. [1895 Montgomery Ward catalogue, p.245]
kebab (n.): "pieces of meat roasted on a skewer," 1813 (cf. shish kebab).
keck (v.): "to make a sound as if to vomit," 1530s, echoic. Related: Kecked; kecking.
Ked: proprietary name of a brand of canvas sneakers, 1917, registered by United States Rubber Co., N.Y.
We wanted to call it Peds, but ... it came too close to ... other brand names. So we batted it around for awhile and decided on the hardest-sounding letter in the alphabet, K, and called it Keds, that was in 1916. [J.Healey, in R.L. Cohen, "Footwear Industry," x.93]
keel (n.): "lowest timber of a ship or boat," mid-14c., probably from a Scandinavian source, cf. Old Norse kjölr "keel," Danish kjøl, Swedish köl, from Proto-Germanic *keluz, of uncertain origin. Some etymologists say this is unconnected with the keel that means "a ship, barge," which also is the root of Middle Dutch kiel "ship," Old English ceol "ship's prow," Old High German kiel, German Kiel "ship," but the two words have influenced each other. Barnhart, however, calls them cognates. This other word is said to be from Proto-Germanic *keula, from PIE *geul- "rounded vessel." Keel still is used locally in England and U.S. for "flat-bottomed boat," especially on the Tyne.
keel (v.2): "to keep cool," from Middle English kelen, from Old English celan "to cool," from col "cool" (see cool). The form kele (from Old English colian) was used by Shakespeare, but it later was assimilated with the adjective form into the modern verb cool. Cognate with Dutch koelen, Old High German chuolen, German kühlen.
keel (v.1): 1838, American English, from keel (n.). To keel over (1876) is from the nautical image of a ship turning keel-up. Related: Keeled; keeling.
keelboat (n.): 1690s, from keel + boat.
keelhaul (v.): 1660s (the experience itself is described from 1620s), from Dutch kielhalen, literally "to haul under the keel," an old punishment. See keel (n.) + haul (v.). Related: Keelhauled. German kielholen, Danish kjølhale, Swedish kölhala also are from Dutch.
keelson (n.): also kelson, 1620s, altered (by influence of keel (n.)) from Middle English kelsyng (late 13c.), which probably is of Scandinavian origin (cf. Swedish kölsvin, Danish and Norwegian kjølsvin, from root of Old Norse kjölr (see keel (n.)) + swin "swine," used of timber (see swine). Or else from a similar Low German source.
keen (adj.): c.1200, from Old English cene "bold brave," later "clever, wise," from Proto-Germanic *kan- "be able to" (see can). Original prehistoric senses seem to have been both "brave" and "skilled;" cognate with Old Norse kænn "skillful, wise," Middle Dutch coene "bold," Dutch koen, Old High German kuon "pugnacious, strong," German kühn "bold, daring." Sense of "eager" is from mid-14c. The meaning "sharp" is peculiar to English: of blades and edges early 13c., of sounds c.1400, of eyesight c.1720. A popular word of approval in teenager and student slang from c.1900.
keen (v.): "lament," 1811, from Irish caoinim "I weep, wail, lament," from Old Irish coinim "I wail." Related: Keened; keening. As a noun from 1830.
keenly (adv.): Old English cenlice; see keen (adj.) + -ly (2).
keenness (n.): 1520s, from keen (adj.) + -ness.
keep (v.): late Old English cepan "to seize, hold," also "to observe," from Proto-Germanic *kopijanan, but with no certain connection to other languages. It possibly is related to Old English capian "to look," from Proto-Germanic *kap- (cepan was used c.1000 to render Latin observare), which would make the basic sense "to keep an eye on."
The word prob. belongs primarily to the vulgar and non-literary stratum of the language; but it comes up suddenly into literary use c.1000, and that in many senses, indicating considerable previous development. [OED]
Sense of "preserve, maintain" is from mid-14c. Meaning "to maintain in proper order" is from 1550s; meaning "financially support and privately control" (usually in reference to mistresses) is from 1540s. Related: Kept; keeping.
keep (n.): mid-13c., "care or heed in watching," from keep (v.). Meaning "innermost stronghold of a tower" is from 1580s, perhaps a translation of Italian tenazza, with a notion of "that which keeps" (someone or something); the sense of "food required to keep a person or animal" is attested from 1801. For keeps "completely, for good" is American English colloquial, from 1861.
keeper (n.): c.1300 (late 13c. as a surname), "one who has charge of some person or thing, warden," agent noun from keep (v.). Sense of "one who carries on some business" is from mid-15c. Sporting sense (originally cricket) is from 1744. Meaning "something (or someone) worth keeping" is attested by 1999. Brother's keeper is from Genesis iv:9.
keepsake (n.): 1790, from keep (v.) + sake; on model of namesake; thus an object kept for the sake of the giver. As an adjective by 1839.
kef (n.): 1808, from Arabic kaif "well-being, good-humor." Specifically, state of dreaming intoxication produced by smoking cannabis; dolce far niente. In Morocco and Algeria, it was the name for Indian hemp.
keg (n.): 1630s, earlier kag (mid-15c.), from a Scandinavian source, cf. Old Norse kaggi "keg, cask," of unknown origin. Cognate with Swedish kagge, Norwegian kagg. Specific sense of "barrel of beer" is from 1945. U.S. student slang kegger "party featuring a keg of beer" attested by 1969.
keister (n.): "buttocks," 1931, perhaps transferred from underworld meaning "safe, strongbox" (1914), earlier "a burglar's toolkit that can be locked" (1881); probably from British dialect kist (northern form of chest) or its German cognate Kiste "chest, box." The connection may be via pickpocket slang sense of "rear trouser pocket" (1930s).
keld (n.): 1690s in northern dialect, but frequent in place names, from Old Norse kelda "a well, fountain, spring," also "a deep, still, smooth part of a river."
Kellogg: surname, attested from late 13c., literally "kill hog," a name for a butcher. The U.S. cereal company began in Battle Creek, Michigan, in 1906, founded by W.K. Kellogg (business manager of the Battle Creek Sanatorium) as Battle Creek Toasted Corn Flake Company.
Kelly: common Irish surname, from Old Irish ceallach "war." As a type of pool played with 15 balls, it is attested from 1898. Kelly green first recorded 1917.
keloid (n.): also cheloid, 1854, from French kéloïde, from Greek khele "crab claw, talon, cloven hoof" + -oides (see -oid). Related: Keloidal; cheloidal.
kelp (n.): 1660s, from Middle English culpe (late 14c.), of unknown origin. Kelper "native or inhabitant of the Falkland Islands" is attested from 1960.
kelpie (n.): 1747, Scottish, of unknown origin, perhaps related to Gaelic colpach "heifer, steer, colt;" colpa "cow, horse." The Lowland name of a demon in the shape of a horse that was reputed to haunt lakes and rivers and to delight in causing drownings. But unlike its equivalents in Danish (nøkken) and Icelandic (nykur), it occasionally was benevolent, especially to millers by keeping their streams running.
Kelvin: unit of absolute temperature scale, 1911, in honor of British physicist Sir William Thompson, Lord Kelvin (1824-1907).
kempt (adj.): "well-combed, neat," late 14c., from past tense of dialectal kemb, from Old English cemdan (see unkempt). A rare word after c.1500; any modern use probably is a whimsical back-formation from unkempt.
ken (v.): "to know," Scottish dialect, from Old English cennan "make known, declare, acknowledge" (in late Old English also "to know"), originally "make to know," causative of cunnan "to become acquainted with, to know" (see can (v.)). Cognate with German kennen, Danish kjende, Swedish känna. Related: Kenned; kenning.
ken (n.2): "house where thieves meet," 1560s, vagabonds' slang, probably a shortening of kennel.
ken (n.1): "range of sight," 1580s, a nautical abbreviation of kenning.
kendal (n.): green woolen cloth, late 14c., from place name in Westmoreland where it was manufactured. The place so called for being in the dale of the River Kent.
Kenelm: masc. proper name, Old English Cenhelm, from cene "brave, bold" (see keen (adj.)) + helm "helmet" (see helmet).