Online Etymology Dictionary

school (n.1): "place of instruction," Old English scol, from Latin schola "intermission of work, leisure for learning; learned conversation, debate; lecture; meeting place for teachers and students, place of instruction; disciples of a teacher, body of followers, sect," from Greek skhole "spare time, leisure, rest ease; idleness; that in which leisure is employed; learned discussion;" also "a place for lectures, school;" originally "a holding back, a keeping clear," from skhein "to get" (from PIE root *segh- "to hold, hold in one's power, to have;" see scheme (n.)) + -ole by analogy with bole "a throw," stole "outfit," etc.

The original notion is "leisure," which passed to "otiose discussion" (in Athens or Rome the favorite or proper use for free time), then "place for such discussion." The Latin word was widely borrowed (Old French escole, French école, Spanish escuela, Italian scuola, Old High German scuola, German Schule, Swedish skola, Gaelic sgiol, Welsh ysgol, Russian shkola). Translated in Old English as larhus, literally "lore house," but this seems to have been a glossary word only.

Meaning "students attending a school" in English is attested from c. 1300; sense of "school building" is first recorded 1590s. Sense of "people united by a general similarity of principles and methods" is from 1610s; hence school of thought (1864). School of hard knocks "rough experience in life" is recorded from 1912 (in George Ade); to tell tales out of school "betray damaging secrets" is from 1540s. School bus is from 1908. School days is from 1590s. School board from 1870.
school (n.2): "group of fish," c. 1400, from Middle Dutch schole (Dutch school) "group of fish or other animals," cognate with Old English scolu "band, troop, crowd of fish," from West Germanic *skulo- (source also of Old Saxon scola "troop, multitude," West Frisian skoal), perhaps with a literal sense of "division," from PIE root *(s)kel- (1) "to cut, divide" (see scale (n.1)). Compare shoal (n.2)). For possible sense development, compare section (n.) from Latin secare "to cut."
school (v.1): "to educate; to reprimand, to discipline," mid-15c., from school (n.1). Related: Schooled; schooling.
school (v.2): "collect or swim in schools," 1590s, from school (n.2). Related: Schooled; schooling.
school-book (n.): also schoolbook, 1745, from school (n.1) + book (n.).
schoolboy (n.): 1580s, from school (n.1) + boy. As an adjective from 1874. Related: Schoolboyish.
schooled (adj.): "taught, trained, disciplined," 1821, past participle adjective from school (v.1).
schoolgirl (n.): 1777, from school (n.1) + girl. As an adjective from 1922.
schooling (n.): mid-15c. "act of teaching; fact of being taught," verbal noun from school (v.1).
schoolmarm (n.): also school-marm, "female school teacher," 1834, American English colloquial, in countrified humor writing of "Major Jack Downing" of Maine (Seba Smith); variant of school-ma'am (1828), American English, from school (n.1) + ma'am. See R. Used figuratively from 1887 in reference to patronizing and priggish instruction.
schoolroom (n.): 1773, from school (n.1) + room (n.).
schooner (n.): fore-and-aft rigged vessel, originally with only two masts, 1716, perhaps from a New England verb related to Scottish scon "to send over water, to skip stones." Skeat relates this dialectal verb to shunt. Spelling probably influenced by Dutch, but Dutch schoener is a loan-word from English, as are German Schoner, French schooner, Swedish skonert. Said to have originated in Gloucester, Mass., shipyard.
The rig characteristic of a schooner has been defined as consisting essentially of two gaff sails, the after sail not being smaller than the fore, and a head sail set on a bowsprit. [OED]
Meaning "tall beer glass" is from 1879, of unknown origin or connection.
schottische (n.): round dance resembling a polka, 1849, from German Schottische, from schottische (tanz) "Scottish (dance)," from Schotte "a native of Scotland," from Old High German Scotto, from Late Latin Scottus (see Scot). The pronunciation is French.
schuhplattler (n.): lively Alpine folk dance, 1874, from German Schuhplattler, from schuh "shoe" (see shoe (n.)) + south German dialectal plattler, from platteln "to dance."
Schutzstaffel: internal security force of Nazi Germany, 1930, German, literally "defense squadron." Better known by its initials, S.S.
schvartze (n.): also schvartzer, "black person" (somewhat derogatory), 1961, Yiddish, from schvarts "black" (see swarthy). Perhaps originally a code word to refer to black servants when they were within earshot, as German cognate Schwarze appears to have been used mid-19c.:
In Baltimore in the 80s of the last century, the German-speaking householders, when they had occasion to speak of Negro servants in their presence, called them die Blaue (blues). In the 70s die Schwartze (blacks) had been used, but it was believed that the Negroes had fathomed it. [H.L. Mencken, "The American Language," Supplement I, 1945]
schwa (n.): 1895, from German Schwa, ultimately from Hebrew shewa "a neutral vowel quality," literally "emptiness."
Schwenkfeldian: 1560s, from Casper Schwenkfeld (1490-1561), Silesian Protestant mystic who founded the sect. Schwenkfelder is attested from 1882.
sciamachy (n.): "fighting with shadows, shadow-boxing" 1620s, from Greek skiamakhia "shadow-fighting, a sham fight" but perhaps literally "fighting in the shade" (i.e., in school; ancient teachers taught in shaded public places such as porches and groves), from skia "shade, shadow" (see shine (v.)) + makhe "battle" (see -machy).
sciatic (adj.): "pertaining to the hip," also in reference to the large nerve from the pelvis to the thigh, 1540s, from Middle French sciatique (14c.), from Medieval Latin sciaticus (see sciatica).
sciatica (n.): late 14c., from Medieval Latin sciatica, in sciatica passio "sciatic disease," fem. of sciaticus "sciatic," corruption of Latin ischiadicus "of pain in the hip," from Greek iskhiadikos, from iskhias (genitive iskhiados) "pain in the hips," from iskhion "hip joint."
science (n.): mid-14c., "what is known, knowledge (of something) acquired by study; information;" also "assurance of knowledge, certitude, certainty," from Old French science "knowledge, learning, application; corpus of human knowledge" (12c.), from Latin scientia "knowledge, a knowing; expertness," from sciens (genitive scientis) "intelligent, skilled," present participle of scire "to know," probably originally "to separate one thing from another, to distinguish," related to scindere "to cut, divide," from PIE root *skei- "to cut, to split" (source also of Greek skhizein "to split, rend, cleave," Gothic skaidan, Old English sceadan "to divide, separate;" see shed (v.)).

From late 14c. in English as "book-learning," also "a particular branch of knowledge or of learning;" also "skillfulness, cleverness; craftiness." From c. 1400 as "experiential knowledge;" also "a skill, handicraft; a trade." From late 14c. as "collective human knowledge" (especially "that gained by systematic observation, experiment, and reasoning). Modern (restricted) sense of "body of regular or methodical observations or propositions concerning a particular subject or speculation" is attested from 1725; in 17c.-18c. this concept commonly was called philosophy. Sense of "non-arts studies" is attested from 1670s.
Science, since people must do it, is a socially embedded activity. It progresses by hunch, vision, and intuition. Much of its change through time does not record a closer approach to absolute truth, but the alteration of cultural contexts that influence it so strongly. Facts are not pure and unsullied bits of information; culture also influences what we see and how we see it. Theories, moreover, are not inexorable inductions from facts. The most creative theories are often imaginative visions imposed upon facts; the source of imagination is also strongly cultural. [Stephen Jay Gould, introduction to "The Mismeasure of Man," 1981]

In science you must not talk before you know. In art you must not talk before you do. In literature you must not talk before you think. [John Ruskin, "The Eagle's Nest," 1872]
The distinction is commonly understood as between theoretical truth (Greek episteme) and methods for effecting practical results (tekhne), but science sometimes is used for practical applications and art for applications of skill. To blind (someone) with science "confuse by the use of big words or complex explanations" is attested from 1937, originally noted as a phrase from Australia and New Zealand.
science fiction (n.): 1929 (first attested in advertisements for "Air Wonder Stories" magazine), though there is an isolated use from 1851; abbreviated form sci-fi is from 1955. Earlier in same sense was scientifiction (1916).
scienter (adv.): legalese Latin, literally "knowingly," from sciens, present participle of scire "to know" (see science) + adverbial suffix -ter.
scientific (adj.): 1580s, from Middle French scientifique, from Medieval Latin scientificus "pertaining to science," from Latin scientia "knowledge" (see science) + -ficus "making" + facere "to make" (see factitious). Originally used to translate Greek epistemonikos "making knowledge" in Aristotle's "Ethics."

Sciential (mid-15c., "based on knowledge," from Latin scientialis) is the classical purists' choice for an adjective based on science. Scientic (1540s) and scient (late 15c.) also have been used. First record of scientific revolution is from 1803; scientific method is from 1854; scientific notation is from 1961. Related: Scientifical; scientifically.
scientist (n.): 1834, a hybrid coined from Latin scientia (see science) by the Rev. William Whewell (1794-1866), English polymath, by analogy with artist, in the same paragraph in which he coined physicist (q.v.).
Scientology (n.): 1951, system of beliefs founded by L. Ron Hubbard. According to www.scientology.org:
The word Scientology, conceived by L. Ron Hubbard, comes from the Latin scio which means "knowing, in the fullest meaning of the word" and the Greek word logos which means "study of." It means knowing how to know. Scientology is further defined as "the study and handling of the spirit in relationship to itself, universes and other life."
There was a German scientologie (A. Nordenholz, 1937).
scilicet: late 14c., Latin, "you may know, you may be sure, it is certain," used in sense "that is to say, namely," contraction of scire licit "it is permitted to know," from scire "to know" (see science); for second element see licit. Used as was Old English hit is to witanne, literally "it is to wit" (see wit (v.)). Often abbreviated sc. or scil.
Its function is to introduce : (a) a more intelligible or definite substitute, sometimes the English, for an expression already used ... (b) a word &c. that was omitted in the original as unnecessary, but is thought to require specifying for the present audience .... [Fowler]
Scilly: isles off Cornwall, of unknown origin. Pliny has Silumnus, Silimnis. Perhaps connected with the Roman god Sulis (compare Aquae sulis "Bath"). The -y might be Old Norse ey "island" The -c- added 16c.-17c. "[A]bout the only certain thing that can be said is that the c of the modern spelling is not original but was added for distinction from ModE silly as this word developed in meaning from 'happy, blissful' to 'foolish.'" [Victor Watts, "Cambridge Dictionary of English Place-Names," 2004].
scimitar (n.): 1540s, cimiterie, from Middle French cimeterre (15c.) or Italian scimitarra, of uncertain origin. Turkish would be the expected source, but no such word has been found there. Perhaps from Persian shimshir (pronounced "shamsher," compare Greek sampsera "a barbarian sword," from this source), but OED finds this "unsatisfactory as to form." Many early variations; the modern spelling is from influence of the Italian form of the word. Century Dictionary (1902) has simitar as preferred spelling.
scintilla (n.): 1690s, "spark, glimmer," hence "least particle, trace," from figurative use of Latin scintilla "particle of fire, spark, glittering speck, atom," probably from PIE *ski-nto-, from root *skai- "to shine, to gleam" (source also of Gothic skeinan, Old English scinan "to shine;" see shine (v.)).
scintillate (v.): 1620s, from Latin scintillatus, past participle of scintillare "to sparkle, glitter, gleam, flash," from scintilla "spark" (see scintilla). Related: Scintillated; scintillating.
scintillation (n.): 1620s, from Latin scintilationem (nominative scintillatio), noun of action from past participle stem of scintillare (see scintillate).
sciolism (n.): "a show of knowledge," 1798; see sciolist + -ism.
sciolist (n.): 1610s, "smatterer, pretender to knowledge," from Late Latin sciolus "one who knows a little," diminutive of scius "knowing," from scire "to know" (see science) + -ist. Related: Sciolistic.
sciomancy (n.): "divination by ghostly communication," 1620s, from Modern Latin sciomantia, from scio-, Latinized comb. form of Greek skia "shade, shadow" (see shine (v.)) + Latinized form of Greek manteia (see -mancy).
scion (n.): c. 1300, "a shoot or twig," especially one for grafting, from Old French sion, cion "descendant; shoot, twig; offspring" (12c., Modern French scion, Picard chion), of uncertain origin. OED rejects derivation from Old French scier "to saw." Perhaps a diminutive from Frankish *kid-, from Proto-Germanic *kidon-, from PIE *geie- "to sprout, split, open" (see chink (n.1)). Figurative use is attested from 1580s in English; meaning "an heir, a descendant" is from 1814, from the "family tree" image.
sciophobia (n.): "fear of shadows," 1977, from scio-, Latinized comb. form of Greek skia "shade, shadow" (see shine (v.)) + -phobia. Related: sciophobe; sciophobic.
scirrhous (n.): 1560s, from Middle French scirrheux (16c., Modern French squirreux), from Modern Latin scirrhosus, from Latin scirros "a hard swelling, tumor," from Greek skirrhos "hard tumor," from skiros (adj.) "hard," of unknown origin.
scission (n.): "act of cutting or dividing," mid-15c., from French scission (14c.), from Late Latin scissionem (nominative scissio) "a cleaving, dividing," noun of action from past participle stem of Latin scindere "to cut" (see shed (v.)).
scissor (v.): 1610s, "to cut with scissors;" 1961 with reference to leg motions (in the wrestling sense it is attested from 1968); see scissors. Related: Scissored; scissoring.
scissors (n.): late 14c., sisoures, from Old French cisoires (plural) "shears," from Vulgar Latin *cisoria (plural) "cutting instrument," from *cisus (in compounds such as Latin excisus, past participle of excidere "to cut out"), ultimately from Latin caedere "to cut" (see -cide). Spelling with sc- is 16c., from influence of Medieval Latin scissor "tailor," in classical Latin "carver, cutter," from past participle stem of scindere "to split."

Usually with pair of (attested from c. 1400) when indication of just one is required, but a singular form without the -s occasionally was used (cysowre, mid-15c.). In Scotland, shears answers for all sizes, according to OED; but in England generally that word is used only for those too large to be worked by one hand. Sense in wrestling is from 1904. Oh scissors! was a 19c. exclamation of impatience or disgust (1843). In reference to a type of swimming kick, from 1902 (the image itself is from 1880s).
SCLC (n.): initialism (acronym) of Southern Christian Leadership Conference, founded 1957 by the Rev. Martin Luther King Jr., Bayard Rustin, and others.
sclera (n.): 1886, medical Latin, from Greek sklera (menix) "the hard (membrane)," fem. of skleros "hard" (see sclerosis).
sclero-: before vowels scler-, word-forming element meaning "hard," from Latinized form of Greek sklero-, comb. form of skleros "hard," related to skellein "to dry up, parch," from PIE *skle-ro-, from root *skele- "to parch, wither."
scleroderma (n.): 1866, from Modern Latin, from Greek skleros "hard" (see sclerosis) + derma "skin" (see derma). Related: Sclerodermatous; sclerodermatic.
sclerosis (n.): "morbid hardening of the tissue," late 14c., from Medieval Latin sclirosis "a hardness, hard tumor," from Greek sklerosis "hardening," from skleros "hard" (see sclero-). Figurative use by 1954.
sclerotic (adj.): early 15c., "pertaining to sclerosis," from medical Latin scleroticus, from Greek skleroun (see sclerosis). Figurative meaning "unchanging, rigid" is from 1961.
scoff (v.): mid-14c., "jest, make light of something;" mid-15c., "make fun of, mock," from the noun meaning "contemptuous ridicule" (c. 1300), from a Scandinavian source such as Old Norse skaup, skop "mockery, ridicule," Middle Danish skof "jest, mockery;" perhaps from Proto-Germanic *skub-, *skuf- (source also of Old English scop "poet," Old High German scoph "fiction, sport, jest, derision"), from PIE *skeubh- "to shove" (see shove (v.)).
scoffer (n.): late 15c., agent noun from scoff (v.).