Online Etymology Dictionary

scroll (v.): "to write down in a scroll," c. 1600, from scroll (n.). Sense of "show a few lines at a time" (on a computer or TV screen) first recorded 1981. Related: Scrolled; scrolling.
Linux: computer operating system, named for Linux kernel, written 1991 by software engineer Linus Torvalds (b. 1969) of Finland (who coined the word but did not choose it as the name).
liveware (n.): "people," 1966, computer-programmer jargon, from live (adj.) + ending abstracted from software, etc. Compare old nautical slang live lumber "landsmen on board a ship" (1785).
browser (n.): 1845, "animal which browses," agent noun from browse (v.). In the computer sense by 1982.
The first browser was invented at PARC by Larry Tesler, now a designer at Apple Computer. Tesler's first Smalltalk browser was a tree-structured device. It enabled programmers to hunt quickly for items in a Smalltalk dictionary. ["InfoWorld" magazine, vol. v., no. 4, Jan. 24, 1983]
hacker (n.): early 13c. (as a surname), "a chopper, cutter," perhaps also "one who makes hacking tools," agent noun from hack (v.1).

Meaning "one who gains unauthorized access to computer records" is attested by 1975, and this sense seems to suggest hack (v.1), but the computer use is said to be from slightly earlier tech slang sense of "one who works like a hack at writing and experimenting with software, one who enjoys computer programming for its own sake," reputedly a usage that evolved at Massachusetts Institute of Technology (however an MIT student from the late 1960s recalls hack (n.) being used then and there in the general sense of "creative prank." This suggests rather a connection with hack (n.2) via the notion of "plodding, routine work." There may be a convergence of both words here.
cursor (n.): computer sense is 1967 extension of name for the sliding part of a slide rule or other instrument (1590s), earlier "a running messenger" (c. 1300), from Latin cursor "runner," also "errand-boy," from curs-, past participle stem of currere "to run" (see current (adj.)).
ENIAC: acronym from "electronic numeral integrator and computer," device built 1946 at University of Pennsylvania by John W. Mauchly Jr., J. Presper Eckert Jr., and J.G. Brainerd. It cost $400,000, used 18,000 radio tubes, and was housed in a 30-foot-by-50-foot room.
viral (adj.): "of the nature of, or caused by, a virus," 1944, see virus + -al (1). Sense of "become suddenly widely popular through Internet sharing" is attested by 1999, originally in reference to marketing and based on the similarity of the effect to the spread of a computer virus. Related: Virally.
brainiac (n.): "very smart person," 1982, U.S. slang, from brain (n.) + ending from ENIAC, etc. Brainiac also was the name of a comic book villain in the Superman series and a do-it-yourself computer building kit, both from the late 1950s, and the word may bear traces of either or both of these.
hack (v.2): "illegally enter a computer system," by 1984; apparently a back-formation from hacker. Related: Hacked; hacking (1975 in this sense). Earlier verb senses were "to make commonplace" (1745), "make common by everyday use" (1590s), "use (a horse) for ordinary riding" (1560s), all from hack (n.2).
megabyte (n.): 1972, from mega- + byte.
The Sussex team has run the Forrester/Meadows models more than 1000 times on the UK's most powerful computer (the giant two-megabyte IBM 370/165 at Harwell). ["New Scientist," May 4, 1972]
operate (v.): c. 1600, "to be in effect," back-formation from operation, or else from Latin operatus, past participle of operari "to work, labor, toil, take pains" (in Late Latin "to have effect, be active, cause"). Surgical sense is first attested 1799. Meaning "to work machinery" is from 1864 in American English. Related: Operated; operating. Operating system in the computer sense is from 1961.
virtual (adj.): late 14c., "influencing by physical virtues or capabilities, effective with respect to inherent natural qualities," from Medieval Latin virtualis, from Latin virtus "excellence, potency, efficacy," literally "manliness, manhood" (see virtue). The meaning "being something in essence or effect, though not actually or in fact" is from mid-15c., probably via sense of "capable of producing a certain effect" (early 15c.). Computer sense of "not physically existing but made to appear by software" is attested from 1959.
Algol: Beta Persei, variable star in the constellation Perseus, late 14c., literally "the Demon," from Arabic al-ghul "the demon" (see ghoul). It corresponds, in modern representations of the constellation, to the gorgon's head Perseus is holding, but it probably was so called because it visibly varies in brightness every three days, which sets it apart from other bright stars. The computer language (1959) is a contraction of algo(rithmic) l(anguage); see algorithm.
interface (n.): 1874, "a plane surface regarded as the common boundary of two bodies," from inter- + face (n.). Modern use is perhaps a c. 1960 re-coinage; McLuhan used it in the sense "place of interaction between two systems" (1962) and the computer sense "apparatus to connect two devices" is from 1964. As a verb from 1967. Related: Interfaced; interfacing.
binary (adj.): "dual," mid-15c., from Late Latin binarius "consisting of two," from bini "twofold, two apiece, two-by-two" (used especially of matched things), from bis "double" (see bis-). Binary code in computer terminology was in use by 1952, though the idea itself is ancient. Binary star in astronomy is from 1802.
Isidore: masc. proper name, from French, from Latin Isidorus, from Greek Isidoros, literally "gift of Isis," from Isis (see Isis) + doron "gift" (see date (n.1)). St. Isidore, archbishop of Seville (600-636) wrote important historical, etymological, and ecclesiastical works and in 2001 was named patron saint of computers, computer users, and the Internet. Related: Isidorian.
loop (n.): late 14c., "loop of cloth, rope, leather, etc.," probably of Celtic origin (compare Gaelic lub "bend," Irish lubiam), influenced by or blended with Old Norse hlaup "a leap, run" (see leap (v.)). In reference to magnetic recording tape or film, first recorded 1931. Computer programming sense first attested 1947.
menu (n.): 1837, from French menu de repas "list of what is served at a meal," from Middle French menu (adj.) "small, detailed" (11c.), from Latin minutus "small," literally "made smaller," past participle of minuere "to diminish," from root of minus "to diminish" (see minus). Computer usage is from 1967, from expanded sense of "any detailed list," first attested 1889.
function (n.): 1530s, "one's proper work or purpose; power of acting in a specific proper way," from Middle French fonction (16c.) and directly from Latin functionem (nominative functio) "a performance, an execution," noun of action from funct-, past participle stem of fungi "perform, execute, discharge," from PIE root *bheug- (2) "to use, enjoy" (see brook (v.)). Meaning "official ceremony" is from 1630s, originally in church use. Use in mathematics probably was begun by Leibnitz (1692). In reference to computer operations, 1947.
photoshop (v.): "to edit an image using a computer program," 1992, originally, and properly still, only in reference to Photoshop, a bitmap graphics editor trademarked and published by Adobe, released in 1990. Like Taser and Dumpster, it has a tendency to become generic, but if you use it that way in print their lawyers will still send you The Letter. Related: Photoshopped; photoshopping.
avatar (n.): 1784, "descent of a Hindu deity," from Sanskrit avatarana "descent" (of a deity to the earth in incarnate form), from ava- "off, down" (from PIE *au- (2) "off, away") + base of tarati "(he) crosses over," from PIE root *tere- (2) "to cross over" (see through). In computer use, it seems to trace to the novel "Snowcrash" (1992) by Neal Stephenson.
kludge: a fanciful, humorous coinage by U.S. author Jackson W. Granholm (1921-2007), "ill-assorted collection of poorly-matching parts, forming a distressing whole" (Granholm's definition), 1962, also as a verb. It persisted in the jargon of computer programmers for quick-and-dirty fixes in code. Related: Kludged; kludgy.
printer (n.): c. 1500, "person who prints books, etc.," agent noun from print (v.). As a mechanical device from 1859, originally in telegraphy. In the computer sense, from 1946. Printer's bible (c. 1702) so called from mistaken substitution of printers for princes in Psalm cxix:161, which led to the misreading:
Printers have persecuted me without a cause.
toolbar (n.): 1960 as a frame fitted to a tractor to hold tools; from tool (n.) + bar (n.1). Computer sense is attested from 1991.
Among 100-odd new features in Excel 3.0 is a row of "buttons" on the screen called the Toolbar. Located under the pull-down menus, the Toolbar provides rapid access to frequently used commands. ["Popular Science," April 1991.]
game (v.): Middle English gamen "to sport, joke, jest," from Old English gamenian "to play, jest, joke;" see game (n.). The Middle English word is little recorded from c. 1400 and modern use for "to play at games" (1520s) probably is a new formation from the noun; and it might have been re-re-coined late 20c. in reference to computer games. Related: Gamed; gaming.
load (v.): late 15c., "to place in or on (a vehicle)," from load (n.). Sense of "add to the weight of, put a load in or on" is from c. 1500; sense of "to charge a firearm" is from 1620s. Intransitive sense "put or take on a load or charge" is from 1720; of a vehicle, "to fill with passengers," from 1832. Of computer files or programs, by 1977. Related: Loaded; loaden (obs.); loading.
mega-: before vowels meg-, word-forming element often meaning "large, great," but in precise scientific language "one million" (megaton, megawatt, etc.), from Greek megas "great, large, vast, big, high, tall; mighty, important" (fem. megale), from PIE *meg- "great" (source also of Latin magnus, Old English micel; see mickle). Mega began to be used alone as an adjective by 1982.
High-speed computer stores 2.5 megabits [headline in "Electronics" magazine, Oct. 1, 1957]
stack (n.): c. 1300, "pile, heap, or group of things," from a Scandinavian source akin to Old Norse stakkr "haystack" (cognate with Danish stak, Swedish stack "heap, stack"), from Proto-Germanic *stakon- "a stake," from PIE *stog- (source also of Old Church Slavonic stogu "heap," Russian stog "haystack," Lithuanian stokas "pillar"), variant of root *steg- (1) "pole, stick" (see stake (n.)). Meaning "set of shelves on which books are set out" is from 1879. Used of the chimneys of factories, locomotives, etc., since 1825. Of computer data from 1960.
file (n.1): 1520s, "string or wire on which documents are strung," from French file "a row" (15c.), noun derived from Middle French filer "string documents; spin thread" (see file (v.1)). The literal sense explains why from the beginning until recently things were generally on file (or upon file). The meaning "collection of papers systematically arranged for ready reference" is from 1620s; computer sense is from 1954. The sense "row of persons or things one behind another" (1590s) is originally military, from the French verb in the sense of "march in file." Meaning "line of squares on a chessboard running directly from player to player" is from 1610s.
flame (v.): Middle English flaumen, also flaumben, flomben, flamben, flamen, flammen, c. 1300 (implied in flaming "to shine (like fire), gleam, sparkle like flames;" mid-14c. as "emit flames, be afire, to blaze," from Anglo-French flaumer, flaumber (Old French flamber) "burn, be on fire, be alight" (intransitive), from flamme "a flame" (see flame (n.)).

Transitive meaning "to burn, set on fire" is from 1580s. Meaning "break out in violence of passion" is from 1540s; the sense of "unleash invective on a computer network" is from 1980s. Related: Flamed; flaming. To flame out, in reference to jet engines, is from 1950.
toast (n.2): "piece of bread browned by fire or dry heat," early 15c., from toast (v.1); originally as something added to wine, ale, etc. From 17c. in the modern sense as something eaten on its own with a spread. Slang meaning "a goner, person or thing already doomed or destroyed" is recorded by 1987, perhaps from notion of computer circuits being "fried," and with unconscious echoes of earlier figurative phrase to be had on toast (1886) "to be served up for eating."
program (n.): 1630s, "public notice," from Late Latin programma "proclamation, edict," from Greek programma "a written public notice," from stem of prographein "to write publicly," from pro- "forth" (see pro-) + graphein "to write" (see -graphy).

General sense of "a definite plan or scheme" is recorded from 1837. Meaning "list of pieces at a concert, playbill" first recorded 1805 and retains the original sense. That of "objects or events suggested by music" is from 1854. Sense of "broadcasting presentation" is from 1923. Computer sense (noun and verb) is from 1945. Spelling programme, established in Britain, is from French in modern use and began to be used early 19c., originally especially in the "playbill" sense. Program music attested from 1877.
random (adj.): "having no definite aim or purpose," 1650s, from at random (1560s), "at great speed" (thus, "carelessly, haphazardly"), alteration of Middle English noun randon "impetuosity, speed" (c. 1300), from Old French randon "rush, disorder, force, impetuosity," from randir "to run fast," from Frankish *rant "a running" or some other Germanic source, from Proto-Germanic *randa (source also of Old High German rennen "to run," Old English rinnan "to flow, to run;" see run (v.)).

In 1980s U.S. college student slang it began to acquire a sense of "inferior, undesirable." (A 1980 William Safire column describes it as a college slang noun meaning "person who does not belong on our dormitory floor.") Random access in reference to computer memory is recorded from 1953. Related: Randomly; randomness.
virus (n.): late 14c., "venomous substance," from Latin virus "poison, sap of plants, slimy liquid, a potent juice," probably from PIE root *weis- "to melt away, to flow," used of foul or malodorous fluids, with specialization in some languages to "poisonous fluid" (source also of Sanskrit visam "poison," visah "poisonous;" Avestan vish- "poison;" Latin viscum "sticky substance, birdlime;" Greek ios "poison," ixos "mistletoe, birdlime;" Old Church Slavonic višnja "cherry;" Old Irish fi "poison;" Welsh gwy "fluid, water," gwyar "blood"). Main modern meaning "agent that causes infectious disease" first recorded 1728 (in reference to venereal disease). The computer sense is from 1972.
down (adv.): late Old English shortened form of Old English ofdune "downwards," from dune "from the hill," dative of dun "hill" (see down (n.2)). A sense development peculiar to English.

Used as a preposition since c. 1500. Sense of "depressed mentally" is attested from c. 1600. Slang sense of "aware, wide awake" is attested from 1812. Computer crash sense is from 1965. As a preposition from late 14c.; as an adjective from 1560s. Down-and-out is from 1889, American English, from situation of a beaten prizefighter. Down home (adj.) is 1931, American English; down the hatch as a toast is from 1931; down to the wire is 1901, from horse-racing. Down time is from 1952. Down under "Australia and New Zealand" attested from 1886; Down East "Maine" is from 1825; Down South "in the Southern states of the U.S." is attested by 1834.
Trojan (adj.): Old English Troian "of or pertaining to ancient Troy," from Latin Trojanus, from Troia, Troja "Troy," from the Greek name for the city, said to be from Tros, name of a king of Phrygia, the mythical founder of Troy. Trojan horse was figurative of ambush-from-within in Roman times (equus Troianus); attested in English from 1570s; the computer virus sense is attested by 1982.

As a noun from mid-14c., "inhabitant of ancient Troy;" in early modern English, the noun could mean "a determined fellow, one who fights or works hard," from the Trojans' long resistance to the Greeks in the Trojan War, but also in 17c., it was a colloquial term for "person of dissolute life, carousing companion." The trade name for a brand of prophylactic contraceptive was registered 1927 in U.S.
mouse (n.): Old English mus "small rodent," also "muscle of the arm," from Proto-Germanic *mus (source also of Old Norse, Old Frisian, Middle Dutch, Danish, Swedish mus, Dutch muis, German Maus "mouse"), from PIE *mus- (source also of Sanskrit mus "mouse, rat," Old Persian mush "mouse," Old Church Slavonic mysu, Latin mus, Lithuanian muse "mouse," Greek mys "mouse, muscle").

Plural form mice (Old English mys) shows effects of i-mutation. Contrasted with man (n.) from 1620s. Meaning "black eye" (or other discolored lump) is from 1842. Computer sense is from 1965, though applied to other things resembling a mouse in shape since 1750, mainly nautical.
Parturient montes, nascetur ridiculus mus [Horace]
system (n.): 1610s, "the whole creation, the universe," from Late Latin systema "an arrangement, system," from Greek systema "organized whole, a whole compounded of parts," from stem of synistanai "to place together, organize, form in order," from syn- "together" (see syn-) + root of histanai "cause to stand" from PIE root *stā- "to stand" (see stet).

Meaning "set of correlated principles, facts, ideas, etc." first recorded 1630s. Meaning "animal body as an organized whole, sum of the vital processes in an organism" is recorded from 1680s; hence figurative phrase to get (something) out of one's system (1900). Computer sense of "group of related programs" is recorded from 1963. All systems go (1962) is from U.S. space program. The system "prevailing social order" is from 1806.
gamer (n.): mid-15c., "an athlete" (mid-13c. as a surname, Johannes le Gamer), agent noun from game (v.). Meaning "one devoted to playing video or computer games" is attested by 1981 (by 1975 in reference to players of Dungeons & Dragons). Gamester is attested from 1580s but also sometimes meant "prostitute" (compare old slang The Game "sexual intercourse" (by 1930s), probably from the first game ever played "copulation"). From 1550s as "a gambler." Gamesman is from 1947.
Quite a few of the gamers we've encountered during our monthly strolls down "Arcade Alley" suffer the same chronic frustration: finding enough opponents to slake their thirst for endless hours of play. ["Video" magazine, May 1981]
bootstrap (n.): also boot-strap, tab or loop at the back of the top of a men's boot, which the wearer hooked a finger through to pull the boots on, 1870, from boot (n.) + strap (n.).

Circa 1900, to pull (oneself) up by (one's) bootstraps was used figuratively of an impossible task (Among the "practical questions" at the end of chapter one of Steele's "Popular Physics" schoolbook (1888) is, "30. Why can not a man lift himself by pulling up on his boot-straps?"). By 1916 its meaning expanded to include "better oneself by rigorous, unaided effort." The meaning "fixed sequence of instructions to load the operating system of a computer" (1953) is from the notion of the first-loaded program pulling itself, and the rest, up by the bootstrap.
level (v.): mid-15c., "to make level" (transitive), from level (n.). From c. 1600 as "to bring to a level." Intransitive sense "cease increasing" is from 1958. Meaning "to aim (a gun)" is late 15c. Slang sense of "tell the truth, be honest" is from 1920. To level up "to rise" is attested by 1863.
A word here as to the misconception labored under by our English neighbor; he evidently does not understand the American manner of doing things. We never level down in this country; we are always at work on the up grade. "Level up! Level up!" is the motto of the American people. [James E. Garretson, "Professional Education," in "The Dental Cosmos," Philadelphia, 1865]
Modern use is mostly from computer gaming (2001). To level off "cease rising or falling" is from 1920, originally in aviation. Related: Levelled; levelling.
hard (adj.): Old English heard "solid and firm, not soft," also, "difficult to endure, carried on with great exertion," also, of persons, "severe, rigorous, harsh, cruel," from Proto-Germanic *hardu- (source also of Old Saxon hard, Old Frisian herd, Dutch hard, Old Norse harðr "hard," Old High German harto "extremely, very," German hart, Gothic hardus "hard"), from PIE *kortu- (source also of Greek kratos "strength," kratys "strong"), suffixed form of root *kar-/*ker- "hard."

Meaning "difficult to do" is from c. 1200. Of water, in reference to the presence of mineral salts, 1650s; of consonants, 1775. Hard of hearing preserves obsolete Middle English sense of "having difficulty in doing something." In the sense "strong, spiritous, fermented" from 1789 (as in hard cider, etc.), and this use probably is the origin of that in hard drugs (1955). Hard facts is from 1853; hard news in journalism is from 1918. Hard copy (as opposed to computer record) is from 1964; hard disk is from 1978; the computer hard drive is from 1983. Hard times "period of poverty" is from 1705. Hard money (1706) is specie, as opposed to paper. Hence 19c. U.S. hard (n.) "one who advocates the use of metallic money as the national currency" (1844). To play hard to get is from 1945. Hard rock as a pop music style recorded from 1967. To do something the hard way is from 1907.
geek (n.): "sideshow freak," 1916, U.S. carnival and circus slang, perhaps a variant of geck "a fool, dupe, simpleton" (1510s), apparently from Dutch gek or Low German geck, from an imitative verb found in North Sea Germanic and Scandinavian meaning "to croak, cackle," and also "to mock, cheat" (Dutch gekken, German gecken, Danish gjække, Swedish gäcka). The modern form and the popular use with reference to circus sideshow "wild men" is from 1946, in William Lindsay Gresham's novel "Nightmare Alley" (made into a film in 1947 starring Tyrone Power).
"An ordinary geek doesn't actually eat snakes, just bites off chunks of 'em, chicken heads and rats." [Arthur H. Lewis, "Carnival," 1970]
By c. 1983, used in teenager slang in reference to peers who lacked social graces but were obsessed with new technology and computers (such as the Anthony Michael Hall character in 1984's "Sixteen Candles").
geek out vi. To temporarily enter techno-nerd mode while in a non-hackish context, for example at parties held near computer equipment. [Eric S. Raymond, "The New Hacker's Dictionary," 1996]
read (v.): Old English rædan (West Saxon), redan (Anglian) "to advise, counsel, persuade; discuss, deliberate; rule, guide; arrange, equip; forebode; read, explain; learn by reading; put in order" (related to ræd, red "advice"), from Proto-Germanic *redan (source also of Old Norse raða, Old Frisian reda, Dutch raden, Old High German ratan, German raten "to advise, counsel, guess"), from PIE root *re(i)- "to reason, count" (source also of Sanskrit radh- "to succeed, accomplish," Greek arithmos "number, amount," Old Church Slavonic raditi "to take thought, attend to," Old Irish im-radim "to deliberate, consider"). Words from this root in most modern Germanic languages still mean "counsel, advise."

Sense of "make out the character of (a person)" is attested from 1610s. Connected to riddle (n.1) via notion of "interpret." Transference to "understand the meaning of written symbols" is unique to Old English and (perhaps under English influence) Old Norse raða. Most languages use a word rooted in the idea of "gather up" as their word for "read" (such as French lire, from Latin legere). Read up "study" is from 1842; read out (v.) "expel by proclamation" (Society of Friends) is from 1788. read-only in computer jargon is recorded from 1961.
memory (n.): mid-13c., "recollection (of someone or something); awareness, consciousness," also "fame, renown, reputation," from Anglo-French memorie (Old French memoire, 11c., "mind, memory, remembrance; memorial, record") and directly from Latin memoria "memory, remembrance, faculty of remembering," noun of quality from memor "mindful, remembering," from PIE root *(s)mer- (1) "to remember" (Sanskrit smarati "remembers," Avestan mimara "mindful;" Greek merimna "care, thought," mermeros "causing anxiety, mischievous, baneful;" Serbo-Croatian mariti "to care for;" Welsh marth "sadness, anxiety;" Old Norse Mimir, name of the giant who guards the Well of Wisdom; Old English gemimor "known," murnan "mourn, remember sorrowfully;" Dutch mijmeren "to ponder"). Meaning "faculty of remembering" is late 14c. in English.
I am grown old and my memory is not as active as it used to be. When I was younger I could remember anything, whether it had happened or not; but my faculties are decaying now and soon I shall be so I cannot remember any but the things that never happened. It is sad to go to pieces like this, but we all have to do it. [Mark Twain, "Autobiography"]
Computer sense, "device which stores information," is from 1946. Related: Memories.
butterfly (n.): Old English buttorfleoge, evidently butter (n.) + fly (n.), but of obscure signification. Perhaps based on the old notion that the insects (or witches disguised as butterflies) consume butter or milk that is left uncovered. Or, less creatively, simply because the pale yellow color of many species' wings suggests the color of butter. Another theory connects it to the color of the insect's excrement, based on Dutch cognate boterschijte. An overview of words for "butterfly" in various languages can be found here. Also see papillon.

Applied to persons from c. 1600, originally in reference to vain and gaudy attire; by 1806 in reference to transformation from early lowly state; in reference to flitting tendencies by 1873. The swimming stroke so called from 1936. Butterflies "light stomach spasms caused by anxiety" is from 1908.
The butterfly effect is a deceptively simple insight extracted from a complex modern field. As a low-profile assistant professor in MIT's department of meteorology in 1961, [Edward] Lorenz created an early computer program to simulate weather. One day he changed one of a dozen numbers representing atmospheric conditions, from .506127 to .506. That tiny alteration utterly transformed his long-term forecast, a point Lorenz amplified in his 1972 paper, "Predictability: Does the Flap of a Butterfly's Wings in Brazil Set Off a Tornado in Texas?" [Peter Dizikes, "The Meaning of the Butterfly," The Boston Globe, June 8, 2008]
K: eleventh Roman letter, from Greek kappa, from Phoenician kaph or a similar Semitic source, said to mean literally "hollow of the hand" and to be so called for its shape.

Little used in classical Latin, which at an early age conformed most of its words (the exceptions had ritual importance) to a spelling using -c- (a character derived from Greek gamma). In Late Latin, pronunciation of -c- shifted (in the direction of "s"). Greek names brought into Latin also were regularized with a -c- spelling, and then underwent the Late Latin sound-shift; hence the modern pronunciation of Cyrus, Circe. To keep their pronunciation clear, the many Greek words (often Church words) that entered Latin after this shift tended to take Latin -k- for Greek kappa.

K- thus became a supplementary letter to -c- in Medieval Latin, used with Greek and foreign words. But most of the languages descended from Latin had little need of it, having evolved other solutions to the sound shifts.

K- also was scarce in Old English. After the Norman conquest, new scribal habits restricted -c- and expanded the use of -k-, which began to be common in English spelling from 13c. This probably was done because the sound value of -c- was evolving in French and the other letter was available to clearly mark the "k" sound for scribes working in English. For more, see C.

In words transliterated from Arabic, Hebrew, Turkish, Japanese, Hawaiian, etc., it represents several different sounds lumped. In modern use some of them are now with kh-; in older borrowings they often followed traditional English spelling and were written with a C- (Corea, Caaba, etc.).

As a symbol for potassium, it represents Latin kalium "potash." In CMYK as a color system for commercial printing it means "black" but seems to stand for key in a specialized printing sense. Slang meaning "one thousand dollars" is 1970s, from kilo-. K as a measure of capacity (especially in computer memory) meaning "one thousand" also is an abbreviation of kilo-.

As an indication of "strikeout" in baseball score-keeping it dates from 1874 and is said to represent the last letter of struck. The invention of the scorecard symbols is attributed to English-born U.S. newspaperman Henry Chadwick (1824-1908) principally of the old New York "Clipper," who had been writing baseball since 1858, and who explained it thus:
Smith was the first striker, and went out on three strikes, which is recorded by the figure "1" for the first out, and the letter K to indicate how put out, K being the last letter of the word "struck." The letter K is used in this instance as being easier to remember in connection with the word struck than S, the first letter, would be. [Henry Chadwick, "Chadwick's Base Ball Manual," London, 1874]