The alliterative phrase kith and kin (late 14c.) originally meant "country and kinsfolk" and is almost the word's only survival in Modern English. Some cognates have evolved different senses, such as Dutch kunde "skill, competence," German Kunde "knowledge, news, tidings."
"knowing, wise," 1630s, from a Scottish and northern English formation from can (v.1) in its sense of "know how to," + -y (2). A doublet of cunning that flowered into distinct senses in Scottish English. In the glossary to Scott's "Heart of Mid-Lothian" (1818) uncanny is defined as "dangerous," while canny, as used in the tale, is defined as "skilful, prudent, lucky ; in a superstitious sense, good-conditioned, and safe to deal with ; trustworthy ; quiet." Cannily is "gently" and canny moment is "an opportune or happy time."
"Knowing," hence, from 18c., "careful, skillful, clever," also "frugal, thrifty," and, from early 19c. (perhaps via Scott's novels) "cautious, wary, shrewd." Often used superciliously of Scots by their southern neighbors (and their American cousins).
The Canny Scot is so well known as scarcely to require description. He carries caution, cunning, and selfishness to excess. Deceitful when a purpose is to be accomplished, he is not habitually deceitful. One thing he never loses sight of—his own interest. But of his own interest he is not the most enlightened judge. ["The Natural History of Scotsmen," in The Argosy, December 1865]
Related: Cannily; canniness.
c. 1200, kene, from Old English cene "bold, brave, fearless," in later Old English "clever, prudent, wise, intelligent," common Germanic (cognate with Old Norse kænn "skillful, wise," Middle Dutch coene "bold," Dutch koen, Old High German kuon "pugnacious, strong," German kühn "bold, daring"), but according to OED there are no cognates outside Germanic and the original meaning is "somewhat obscure"; it seem to have been both "brave" and "skilled." Perhaps the connection notion was "to be able" and the word is connected to the source of can (v.1).
Sense of "eager (to do something), vehement, ardent" is from c. 1300. The physical meaning "sharp, sharp-pointed, sharp-edged" (c. 1200) is peculiar to English. Extended senses from c. 1300: Of sounds, "loud, shrill;" of cold, fire, wind, etc. "biting, bitter, cutting." Of eyesight c. 1720. A popular word of approval in teenager and student slang from c. 1900. Keener was 19c. U.S. Western slang for a person considered sharp or shrewd in bargaining.
Old English agan (past tense ahte) "to have, to own," from Proto-Germanic *aiganan "to possess" (source also of Old Frisian aga "have to, ought to," Old Norse eiga, Old High German eigan, Gothic aigan "to possess, have"), from PIE root *aik- "be master of, possess."
The original sense is obsolete. The meaning "to have to repay, be indebted for" began in late Old English with the phrase agan to geldanne literally "to own to yield," which was used to translate Latin debere (earlier in Old English this would have been sceal "shall"); by late 12c. the phrase had been shortened to simply agan, and own (v.) took over this word's original sense.
The intransitive meaning "be in debt" is from mid-15c. To be owing to "be due or attributable to" is by 1650s.
*gnō-, Proto-Indo-European root meaning "to know."
It forms all or part of: acknowledge; acquaint; agnostic; anagnorisis; astrognosy; can (v.1) "have power to, be able;" cognition; cognizance; con (n.2) "study;" connoisseur; could; couth; cunning; diagnosis; ennoble; gnome; (n.2) "short, pithy statement of general truth;" gnomic; gnomon; gnosis; gnostic; Gnostic; ignoble; ignorant; ignore; incognito; ken (n.1) "cognizance, intellectual view;" kenning; kith; know; knowledge; narrate; narration; nobility; noble; notice; notify; notion; notorious; physiognomy; prognosis; quaint; recognize; reconnaissance; reconnoiter; uncouth; Zend.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit jna- "know;" Avestan zainti- "knowledge," Old Persian xšnasatiy "he shall know;" Old Church Slavonic znati "recognizes," Russian znat "to know;" Latin gnoscere "get to know," nobilis "known, famous, noble;" Greek gignōskein "to know," gnōtos "known," gnōsis "knowledge, inquiry;" Old Irish gnath "known;" German kennen "to know," Gothic kannjan "to make known."
in the figurative sense "wildly irresponsible person, potent person or thing freed from usual restraint," by 1896; in the literal sense an object of dread on old warships; the figurative use probably arose from a celebrated scene in a popular late novel by Victor Hugo:
You can reason with a bull dog, astonish a bull, fascinate a boa, frighten a tiger, soften a lion; no resource with such a monster as a loose cannon. You cannot kill it, it is dead; and at the same time it lives. It lives with a sinister life which comes from the infinite. It is moved by the ship, which is moved by the sea, which is moved by the wind. This exterminator is a plaything. [Victor Hugo, "Ninety Three," 1874]