Online Etymology Dictionary

kind-hearted (adj.): also kindhearted, 1530s; see kind (adj.) + hearted. Related: Kindheartedly, kindheartedness.
kinda: 1890, representing a casual pronunciation of kind of (see kind (n.)). Also sometimes written kinder (1834) but the "humorous -r-" is not meant to be pronounced. Dickens has kiender.
kindergarten (n.): 1852, from German Kinder-Garten (1840), literally "children-garden, garden of children," a metaphoric name from Kinder "children" (plural of Kind "child;" see kin (n.)) + Garten "garden" (see yard (n.1)). Coined by German educator Friedrich Fröbel (1782-1852) in reference to his method of developing intelligence in young children. Compare the double sense in nursery
Kindergarten means a garden of children, and Froebel, the inventor of it, or rather, as he would prefer to express it, the discoverer of the method of Nature, meant to symbolize by the name the spirit and plan of treatment. How does the gardener treat his plants? He studies their individual natures, and puts them into such circumstances of soil and atmosphere as enable them to grow, flower, and bring forth fruit,-- also to renew their manifestation year after year. [Mann, Horace, and Elizabeth P. Peabody, "Moral Culture of Infancy and Kindergarten Guide," Boston, 1863]
The first in England was established 1850 by Johannes Ronge, German Catholic priest; in America, 1868, by Elizabeth Peabody of Boston, Mass. Taken into English untranslated, whereas other nations that borrowed the institution nativized the name (Danish börnehave, Modern Hebrew gan yeladim, literally "garden of children"). Sometimes partially Englished as kindergarden (a form attested by 1879).
kindergartener (n.): 1872, "kindergarten teacher," from kindergarten + -er (1). The German form kindergartner is recorded in American English from 1863. As "kindergarten pupil," attested from 1935.
kindle (v.): c. 1200, cundel, "to set fire to, to start on fire," probably from a Scandinavian source akin to Old Norse kynda "to kindle, to light a fire," Swedish quindla "kindle," all of uncertain origin, + frequentative suffix -le. Figurative use (of feelings, passions, etc.) is from c. 1300. Intransitive sense "to begin to burn, to catch fire" is from c. 1400. Related: Kindled; kindling.

Modern sources do not connect it to Latin candela. In the literal sense, Old English had ontyndan "kindle, set fire to," from tendan "to kindle" (see tinder). The word was influenced in form, and sometimes in Middle English in sense, by kindel "to give birth" (of animals), "bring forth, produce" (c. 1200), from kindel (n.) "offspring of an animal, young one," from Old English gecynd (see kind (n.)) + -el.
kindling (n.): "material for lighting fire," usually dry wood in small pieces, 1510s, verbal noun from kindle (v.). Earlier "a setting alight" (c. 1300).
kindly (adj.): c. 1200, cundelich, "natural, right, lawful," from Old English gecyndelic "natural, innate; in accordance with the laws or processes of nature, suitable, lawful" (of birth, etc.); see kind (adj.) + -ly (1). From late 14c. as "pleasant, agreeable;" from 1560s as "full of loving courtesy." Related: Kindliness. The Old English word also meant "pertaining to generation," hence cyndlim "womb," in plural "genitalia," literally "kind-limb."
kindly (adv.): c. 1200, cundeliche, "natively, congenitally; according to nature," from Old English gecyndelice "naturally;" see kind (adj.) -ly (2). From mid-13c. as "pleasantly, gladly, with kind feelings, in a kind manner." Also in Middle English, "by birth or descent; in the approved manner, properly" (late 14c.).
kindness (n.): c. 1300, "courtesy, noble deeds," from kind (adj.) + -ness. Meanings "kind deeds; kind feelings; quality or habit of being kind" are from late 14c. Old English kyndnes meant "nation," also "produce, an increase."
kindred (n.): c. 1200, perhaps late Old English, kinraden, "family, lineage; race, nation, tribe, people; kinsfolk, blood relations," compound of kin (q.v.) + -rede, from Old English ræden "condition, rule," related to rædan "to advise, rule" (see read (v.)). With intrusive -d- (17c.) probably for phonetic reasons (compare sound (n.1)) but perhaps encouraged by kind (n.). As an adjective, 1520s, from the noun.
kine (n.): archaic plural of cow (n.); a double plural (compare children) or genitive plural of Middle English kye "cows," from Old English cy (genitive cyna), plural of cu "cow."
kinema (n.): former alternative spelling of cinema, with the Greek k-.
kinematics (n.): "science of motion," 1840, from French cinématique (Ampère, 1834), from Greek kinesis "movement, motion," from kinein "to move," from PIE *kie-neu-, suffixed form of root *keie- "set in motion" (see cite). Related: Kinematic (adj.), 1846; kinematical; kinematically.
kinesics (n.): study of body language, 1952, from Greek kinesis "movement, motion," from kinein "to move" (see cite) + -ics. Related: kinesic.
kinesiology (n.): 1894, from Greek kinesis "movement, motion," from kinein "to move" (see cite) + -ology. Related: Kinesiological; kinesiologically.
kinesis (n.): "physical movement, muscular action," 1819, from Greek kinesis "movement, motion," from kinein "to move," from PIE *kie-neu-, suffixed form of root *keie- "set in motion" (see cite).
kinesthesia (n.): also kinaesthesia, "the sense of muscular movement," 1888, Modern Latin compound of elements from Greek kinein "to set in motion; to move" (see cite) + aisthesis "perception" (see anaesthesia). Earlier was kinaesthesis (1880).
kinesthetic (adj.): also kinaesthetic, "pertaining to kinesthesia," 1880, coined by British neurologist Henry Charlton Bastian (1837-1915) from Greek kinein "to move" (see cite) + aisthesis "sensation" (see anaesthesia). The coinage is perhaps on model of aesthetic, prosthetic.
kinesthetics (n.): also kinaesthetics, by 1893, from kinesthetic "pertaining to kinesthesia" + -ics.
kinetic (adj.): "relating to muscular motion," 1841, from Greek kinetikos "moving, putting in motion," from kinetos "moved," verbal adjective of kinein "to move" (see cite).
Buster Keaton's subject was kinetic man, a being he approached with the almost metaphysical awe we reserve for a Doppelgänger. This being was, eerily, himself, played by himself, then later in a projection room, watched by himself: an experience never possible to any generation of actors in the previous history of the world. [Hugh Kenner, "The Counterfeiters," 1968]
From 1855 as "causing motion." Related: Kinetical; kinetically.
kinetics (n.): "science of motion and forces acting on bodies in motion," 1864, from kinetic; see -ics.
kineto-: word-forming element used from late 19c. and meaning "motion," from Greek kineto-, comb. form of kinein "to move" (see cite).
kinfolk (n.): also kin-folk, 1802, principally American English but the earliest references are British; from kin (n.) + folk (n.). Kinsfolk is recorded from 1844.
king (n.): a late Old English contraction of cyning "king, ruler" (also used as a title), from Proto-Germanic *kuningaz (source also of Dutch koning, Old Norse konungr, Danish konge, Old Saxon and Old High German kuning, Middle High German künic, German König).

This is of uncertain origin. It is possibly related to Old English cynn "family, race" (see kin), making a king originally a "leader of the people." Or perhaps it is from a related prehistoric Germanic word meaning "noble birth," making a king etymologically "one who descended from noble birth." The sociological and ideological implications render this a topic of much debate. "The exact notional relation of king with kin is undetermined, but the etymological relation is hardly to be doubted" [Century Dictionary].

General Germanic, but not attested in Gothic, where þiudans (cognate with Old English þeoden "chief of a tribe, ruler, prince, king") was used. Finnish kuningas "king," Old Church Slavonic kunegu "prince" (Russian knyaz, Bohemian knez), Lithuanian kunigas "clergyman" are forms of this word taken from Germanic. Meaning "one who has superiority in a certain field or class" is from late 14c.
As leon is the king of bestes. [John Gower, "Confessio Amantis," 1390]
In Old English, used for chiefs of Anglian and Saxon tribes or clans, of the heads of states they founded, and of the British and Danish chiefs they fought. The word acquired a more imposing quality with the rise of European nation-states, but then it was applied to tribal chiefs in Africa, Asia, North America. The chess piece is so called from c. 1400; the playing card from 1560s; the use in checkers/draughts is first recorded 1820. Three Kings for the Biblical Wise Men is from c. 1200.
[I]t was [Eugene] Field who haunted the declining years of Creston Clarke with his review of that actor's Lear. ... Said he, "Mr. Clarke played the King all the evening as though under constant fear that someone else was about to play the Ace." ["Theatre Magazine," January 1922]
king (adj.): king (n.) applied, at first in natural history, to species deemed remarkably big or dominant, such as king crab (1690s); the U.S. king snake (1737), which attacks other snakes and is regarded especially as the enemy of the rattlesnake; king cobra (1894). In marketing, king-size is from 1939, originally of cigarettes. A king-bolt (1825) was the large bolt connecting the fore part of a carriage with the fore-axle.
The King-snake is the longest of all other Snakes in these parts, but are not common; the Indians make Girdles and Sashes of their Skins, and it is reported by them, that they are not very venemous, and that no other Snake will meddle with them, which I suppose is the Reason that they are so fond of wearing their Skins about their Bodies as they do. [John Brickell, "The Natural History of North-Carolina," Dublin, 1737]
King Kong: U.S. film released 1933.
king's evil (n.): "scrofula," late 14c.; it translates Medieval Latin regius morbus. The name came about because the kings of England and France claimed and were reputed to be able to cure it by their touch. In England, the custom dates from Edward the Confessor and was continued through the Stuarts (Charles II touched 90,798 sufferers) but was ended by the Hanoverians (1714).
kingdom (n.): Old English cyningdom; see king (n.) + -dom. Cognate with Old Saxon kuningdom, Middle Dutch koninghdom, Old Norse konungdomr. The usual Old English word was cynedom; Middle English also had kingrick (for second element, see the first element in Reichstag). Meaning "one of the realms of nature" is from 1690s.

Kingdom-come (n.) "the next world, the hereafter" (1785), originally slang, is from the Lord's Prayer, where it is an archaic simple present subjunctive ("may Thy kingdom come") in reference to the spiritual reign of God or Christ.
kingfish (n.): 1750, a name given to various types of fish deemed exceptionally large or tasty; see king (adj.) + fish (n.). From 1933 as the nickname of U.S. politician Huey Long (1893-1935) of Louisiana.
kingfisher (n.): type of colorful European diving bird, mid-15c., originally king's fisher, for obscure reasons; see king + fisher.
kingly (adj.): late 14c., kyngly; see king (n.) + -ly (1). Related: Kingliness. Similar formation in German königlich, Old Frisian kenenglik, Danish kongelig.
kingmaker (n.): also king-maker, 1590s, originally in reference to Richard Nevil, Earl of Warwick (d. 1471), credited with elevating Edward IV and after restoring Henry VI.
kingpin (n.): also king-pin, 1801 as the name of the large pin in the game of kayles (similar to bowls except a club or stick was thrown instead of a ball; see "Games, Gaming and Gamesters' Laws," Frederick Brandt, London, 1871), from king with a sense of "chief" + pin (n.).

The modern use is mainly figurative and is perhaps from the word's use as synonym for king-bolt (itself from 1825), a large, thick, heavy bolt used in a machinery to couple large parts, but if this is the origin, the figurative use is attested earlier (1867) than the literal (1914).
Kings: biblical book (in the Christian bible two books), late 14c., so called because it tells the histories of the kings of Judah and Israel (except Samuel's and most of David's).
kingship (n.): early 14c., from king (n.) + -ship. Old English had cynescipe.
kink (n.): 1670s, "knot-like contraction or short twist in a rope, thread, hair, etc., originally a nautical term, from Dutch kink "twist in a rope" (also found in French and Swedish), which is probably related to Old Norse kikna "to bend backwards, sink at the knees" as if under a burden (see kick (v.)). Figurative sense of "odd notion, mental twist, whim" first recorded in American English, 1803, in writings of Thomas Jefferson; specifically "a sexual perversion, fetish, paraphilia" is by 1973 (by 1965 as "sexually abnormal person").
kink (v.): 1690s (intransitive), 1800 (transitive), from kink (n.). Related: Kinked; kinking.
kinkajou (n.): Central American mammal, 1796, from French (1670s), from an Algonquian word for the wolverine; the North American word was erroneously transferred by Buffon to the tropical animal.
kinky (adj.): 1844, "full of kinks, twisted, curly," from kink (n.) + -y (2). Meaning "odd, eccentric, crotchety" is from 1859; that of "sexually perverted" is from 1959. Related: Kinkiness.
kino-: before vowels, kin-, word-forming element in use from late 19c. and meaning "motion," from Greek kino-, from kinein "to move" (see cite).
kinship (n.): by 1764, from kin + -ship. Relationship covers the same sense but is a hybrid.
kinsman (n.): "man of the same race or family; one related by blood," c. 1200, kenesmen, from late Old English cynnes mannum; see kin + man. Kinswoman is recorded from c. 1400. "The word is commonly and properly used only of a relative by blood, in contradistinction to relatives by marriage, who are properly termed affines" [Century Dictionary, 1902].
kiosk (n.): 1620s, "kind of open pavilion" (made of light wood, etc., often supported by pillars), from French kiosque (17c.), which is (along with German and Polish kiosk) from Turkish koshk, kiöshk "pavilion, summer house," from Persian kushk "palace, villa; pavilion, portico." They were introduced in Western Europe 17c. as ornaments in gardens and parks. Later of street newsstands (1865), on some resemblance of form, a sense perhaps originally in French. Modern sense influenced by British telephone kiosk (1928).
Kiowa: native people of the U.S. southern Plains, 1810, earlier in Spanish records as Caigua, from a word in the people's language (Kiowa-Tanoan). Bright offers on etymology for it.
Kiplingesque (adj.): 1894, from English author Rudyard Kipling (1865-1936) + -esque.
kipper (n.): Old English cypera "male salmon," perhaps related to coper "reddish-brown metal" (see copper (n.1)), on resemblance of color. Another theory connects it to kip (n.) "sharp, hooked lower jaw of the male salmon in breeding season," which is from Middle English kippen "to snatch, tug, pull," but OED doubts this.

The modern noun usually is a shortening of kippered herring, from a verb meaning "to cure a fish by cleaning, salting, and spicing it" (early 14c.). The earliest attested uses of the verb are to preparing salmon, hence the verb. The modern noun kipper is recorded from 1773 of salmon, 1863 of herring.
kir (n.): "white wine and crème de cassis," 1966 (popular in U.S. 1980s), from Canon Felix Kir (1876-1968), mayor of Dijon, who is said to have invented the recipe.
Kiribati: island nation in the Pacific, formerly Gilbert Islands and named for Capt. Thomas Gilbert, who arrived there 1788 after helping transport the first shipload of convicts to Australia. At independence in 1979 it took the current name, which represents the local pronunciation of Gilbert. Christmas Island, named for the date it was discovered by Europeans, is in the chain and now goes by Kiritimati, likewise a local pronunciation of the English name.
kirk (n.): "church,"c. 1200, surviving as a northern England and Scottish dialectal word, from a Scandinavian source such as Old Norse kirkja "church" (see church (n.)). Hence kirkland "church land" (mid-15c.).
kirsch-wasser (n.): also kirschwasser, "liquor distilled from fermented cherry juice," 1819, from German Kirschwasser, literally "cherry-water;" first element from Middle High German kirse, from Old High German kirsa, from Vulgar Latin *ceresia, from Late Latin cerasium "cherry" (see cherry). For second element, see water (n.1).