Online Etymology Dictionary

Shabbat (n.): 1934, from Hebrew shabbat (see Sabbath). Earlier in English as Shabbos (1870), from Yiddish shabes.
shabbify (v.): 1866, from shabby + -ify. Related: Shabified; shabifying.
shabby (adj.): 1660s, of persons, "poorly dressed," with -y (2) + shab "a low fellow" (1630s), literally "scab" (now only dialectal in the literal sense, in reference to a disease of sheep), from Old English sceabb (the native form of the Scandinavian word that yielded Modern English scab; also see sh-). Similar formation in Middle Dutch schabbich, German schäbig "shabby."

Of clothes, furniture, etc., "of mean appearance, no longer new or fresh" from 1680s; meaning "inferior in quality" is from 1805. Figurative sense "contemptibly mean" is from 1670s. Related: Shabbily; shabbiness. Shabby-genteel "run-down but trying to keep up appearances, retaining in present shabbiness traces of former gentility," first recorded 1754. Related: Shabaroon "disreputable person," c. 1700.
shack (n.): 1878, American English and Canadian English, of unknown origin, perhaps from Mexican Spanish jacal, from Nahuatl (Aztecan) xacalli "wooden hut." Or perhaps a back-formation from dialectal English shackly "shaky, rickety" (1843), a derivative of shack, a dialectal variant of shake (v.). Another theory derives shack from ramshackle.

Slang meaning "house" attested by 1910. In early radio enthusiast slang, it was the word for a room or office set aside for wireless use, 1919, perhaps from earlier U.S. Navy use (1917). As a verb, 1891 in the U.S. West in reference to men who "hole up" for the winter; from 1927 as "to put up for the night;" phrase shack up "cohabit" first recorded 1935 (in Zora Neale Hurston).
shackle (n.): Old English sceacel "shackle, fetter," probably also in a general sense "a link or ring of a chain," from Proto-Germanic *skakula- (source also of Middle Dutch, Dutch schakel "link of a chain, ring of a net," Old Norse skökull "pole of a carriage"), of uncertain origin. According to OED, the common notion of "something to fasten or attach" makes a connection with shake unlikely. Figurative use from early 13c. Related: Shackledom "marriage" (1771); shackle-bone "the wrist" (1570s).
shackle (v.): mid-15c., from shackle (n.). Figurative use from 1560s. Related: Shackled; shackling.
shacklebolt (n.): "bolt which passes through the eyes of a shackle," 1680s, from shackle (n.), which has been used specifically of the bar of a padlock from mid-14c., + bolt (n.).
shad (n.): Old English sceadd "shad," important food fish in the Atlantic, possibly from Scandinavian (Norwegian dialectal skadd "small whitefish"); but compare Welsh ysgadan (plural), Irish and Gaelic sgadan "herring." OED says Low German schade may be from English.

Its importance suggested by its use in forming the common names of U.S. East Coast plants and wildlife whose active period coincides with the running of the shad up rivers, such as shad-bird, shad-bush, shad-flower, shad-fly, shad-frog. From the shape of the fish comes shad-bellied, 1832 in reference to persons, "having little abdominal protuberance;" of coats (1842) "sloping apart in front, cut away," especially in reference to the characteristic garb of male Quakers.
shade (n.): Middle English schade, Kentish ssed, from late Old English scead "partial darkness; shelter, protection," also partly from sceadu "shade, shadow, darkness; shady place, arbor, protection from glare or heat," both from Proto-Germanic *skadwaz (source also of Old Saxon skado, Middle Dutch scade, Dutch schaduw, Old High German scato, German Schatten, Gothic skadus), from PIE *skot-wo-, from root *skot- "dark, shade" (source also of Greek skotos "darkness, gloom," Albanian kot "darkness," Old Irish scath, Old Welsh scod, Breton squeut "darkness," Gaelic sgath "shade, shadow, shelter").

Figurative use in reference to comparative obscurity is from 1640s. Meaning "a ghost" is from 1610s; dramatic (or mock-dramatic) expression "shades of _____" to invoke or acknowledge a memory is from 1818, from the "ghost" sense. Meaning "lamp cover" is from 1780. Sense of "window blind" first recorded 1845. Meaning "cover to protect the eyes" is from 1801. Meaning "grade of color" first recorded 1680s; that of "degree or gradiation of darkness in a color" is from 1680s (compare nuance, from French nue "cloud"). Meaning "small amount or degree" is from 1782.
shade (v.): c. 1400, "to screen from light or heat," from shade (n.). From 1520s as "to cast a shadow over;" figurative use in this sense from 1580s. Sense in painting and drawing is from 1797. In reference to colors, 1819. Related: Shaded; shading.
shade-tree (n.): 1806, from shade (n.) + tree (n.).
shades (n.): "sunglasses," 1958, American English, plural of shade (n.).
shadow (v.): Middle English schadowen, Kentish ssedwi, from late Old English sceadwian "to protect as with covering wings" (also see overshadow), from the root of shadow (n.). Similar formation in Old Saxon skadoian, Dutch schaduwen, Old High German scatewen, German (über)schatten. From mid-14c. as "provide shade;" late 14c. as "cast a shadow over" (literal and figurative), from early 15c. as "darken" (in illustration, etc.). Meaning "to follow like a shadow" is from c. 1600 in an isolated instance; not attested again until 1872. Related: Shadowed; shadowing.
shadow (n.): Old English sceadwe, sceaduwe "the effect of interception of sunlight, dark image cast by someone or something when interposed between an object and a source of light," oblique cases ("to the," "from the," "of the," "in the") of sceadu (see shade (n.)). Shadow is to shade (n.) as meadow is to mead (n.2). Similar formation in Old Saxon skado, Middle Dutch schaeduwe, Dutch schaduw, Old High German scato, German schatten, Gothic skadus "shadow, shade."

From mid-13c. as "darkened area created by shadows, shade." From early 13c. in sense "anything unreal;" mid-14c. as "a ghost;" late 14c. as "a foreshadowing, prefiguration." Meaning "imitation, copy" is from 1690s. Sense of "the faintest trace" is from 1580s; that of "a spy who follows" is from 1859.

As a designation of members of an opposition party chosen as counterparts of the government in power, it is recorded from 1906. Shadow of Death (c. 1200) translates Vulgate umbra mortis (Ps. xxiii:4, etc.), which itself translates Greek skia thanatou, perhaps a mistranslation of a Hebrew word for "intense darkness." In "Beowulf," Gendel is a sceadugenga, a shadow-goer, and another word for "darkness" is sceaduhelm. To be afraid of one's (own) shadow "be very timorous" is from 1580s.
shadow boxing (n.): 1906; see shadow (n.) + box (v.2). To shadow-box (v.) is attested from 1932. Shadow-fight is attested from 1768; also see sciamachy.
shadow-box (n.): protective display case, 1892, from shadow (n.) + box (n.1).
shadow-figure (n.): "silhouette," 1851, from shadow (n.) + figure (n.).
shadowland (n.): also shadow-land, 1821, "abode of ghosts and spirits," from shadow (n.) + land (n.). From 1923 as "indeterminate place."
shadowless (n.): 1630s, from shadow (n.) + -less.
shadowy (adj.): late 14c., shadewy, "full of shadows," also "transitory, fleeting, unreal;" see shadow (n.) + -y (2). From 1797 as "faintly perceptible." Related: Shadowiness. Old English had sceadwig "shady."
Shadrach: name of one of the three children delivered from the "fiery furnace" in Dan. iii:26.
shady (adj.): "affording shade," 1570s; "protected by shade," 1590s; from shade (n.) + -y (2). Meaning "disreputable" (1862) probably is from earlier university slang sense of "of questionable merit, unreliable" (1848). Related: Shadily; shadiness. Old English had sceadlic "shady, 'shadely.'"
Shafi'i (n.): member of one of the four principal schools of Sunni Muslims, 1704, from Arabic, from ash-Shafi'i, cognomen of founder Abu Abdallah Muhammad ibn Idris (767-819). Related: Shafi'ite.
shaft (n.2): "long, narrow passage sunk into the earth," early 15c., probably from shaft (n.1) on notion of "long and cylindrical," perhaps as a translation of cognate Low German schacht in this sense (Grimm's suggestion, though OED is against it). Or it may represent a separate (unrecorded) development in Old English directly from Proto-Germanic *skaftaz if the original sense is "scrape, dig." The slang sense of shaft (n.1) is punned upon in country music song "She Got the Gold Mine, I Got the Shaft," a hit for Jerry Reed in 1982.
shaft (n.1): Old English sceaft "long, slender rod, staff, pole; spear-shaft; spear," from Proto-Germanic *skaftaz (source also of Old Norse skapt, Old Saxon skaft, Old High German scaft, German schaft, Dutch schacht, not found in Gothic), which some connect with a Germanic passive past participle of PIE root *(s)kep- "to cut, to scrape" (source of Old English scafan "to shave, scrape, polish") on notion of "tree branch stripped of its bark." But compare Latin scapus "shaft, stem, shank," Greek skeptron "a staff" (see scepter) which appear to be cognates.

Meaning "beam or ray" (of light, etc.) is attested from c. 1300. Sense of "an arrow" is from c. 1400; that of "a handle" from 1520s. Mechanical sense is from 1680s. Vulgar slang meaning "penis" first recorded 1719 on notion of "columnar part" (late 14c.); hence probably shaft (v.) and the related noun sense "act of unfair treatment" (1959), though some early sources insist this is from the notion of a "wound."
shaft (v.): "treat cruelly and unfairly," by 1958, perhaps from shaft (n.1) with overtones of sodomy. Related: Shafted; shafting.
shag (v.1): "copulate with," 1788, probably from obsolete verb shag (late 14c.) "to shake, waggle," which probably is connected to shake (v.).
And þe boot, amydde þe water, was shaggid. [Wyclif]
Compare shake it in U.S. blues slang from 1920s, ostensibly with reference to dancing. But compare shag (v.), used from 1610s in a sense "to roughen or make shaggy." Also the name of a dance popular in U.S. 1930s and '40s. Related: Shagged; shagging.
shag (n.): 1590s, "cloth having a velvet nap on one side," perhaps from Old English sceacga "rough matted hair or wool," from Proto-Germanic *skagjan (source also of Old Norse skegg, Swedish skägg "beard"), perhaps related to Old High German scahho "promontory," Old Norse skagi "a cape, headland," with a connecting sense of "jutting out, projecting." But the word appears to be missing in Middle English. Of tobacco, "cut in fine shreds," it is recorded from 1789; of carpets, rugs, etc., from 1946.
shag (v.2): in baseball, "to go after and catch" (fly balls), by 1913, of uncertain origin. Century Dictionary has it as a secondary sense of a shag (v.) "to rove about as a stroller or beggar" (1851), which is perhaps from shack (n.) "disreputable fellow" (1680s), short for shake-rag, an old term for a beggar.
shagbark (n.): type of hickory, 1751, from shag (n.) + bark (n.1).
shaggy (adj.): "rough, coarse, unkempt," 1590s, from shag (n.) + -y (2). Related: Shaggily; shagginess. Earlier was shagged, from Old English sceacgede "hairy;" compare Old Norse skeggjaðr, Danish skægget "bearded." The shaggy-dog story as a type of joke is attested from 1944, perhaps from vaudeville.
shah (n.): title of the king of Persia, 1560s, shaw, from Persian shah, shortened from Old Persian xšayathiya "king," from Indo-Iranian *ksayati "he has power over, rules" from PIE *tke- "to gain control of, gain power over" (source also of Sanskrit ksatram "dominion;" Greek krasthai "to acquire, get," kektesthai "to possess"). His wife is a shahbanu (from banu "lady"); his son is a shahzadah (from zadah "son").
shake (n.): late 14c., "charge, onrush," from shake (v.). Meaning "a hard shock" is from 1560s. From 1580s as "act of shaking;" 1660s as "irregular vibration." The hand-grip salutation so called by 1712. As a figure of instantaneous action, it is recorded from 1816. Phrase fair shake "honest deal" is attested from 1830, American English (Bartlett calls it "A New England vulgarism"). The shakes "nervous agitation" is from 1620s. Short for milk shake from 1911. Dismissive phrase no great shakes (1816, Byron) perhaps is from dicing.
shake (v.): Old English sceacan "move (something) quickly to and fro, brandish; move the body or a part of it rapidly back and forth;" also "go, glide, hasten, flee, depart" (related to sceacdom "flight"); of persons or parts of the body, "to tremble" especially from fever, cold, fear" (class VI strong verb; past tense scoc, past participle scacen), from Proto-Germanic *skakanan (source also of Old Norse, Swedish skaka, Danish skage "to shift, turn, veer"). No certain cognates outside Germanic, but some suggest a possible connection to Sanskrit khaj "to agitate, churn, stir about," Old Church Slavonic skoku "a leap, bound," Welsh ysgogi "move."

Of the earth in earthquakes, c. 1300. Meaning "seize and shake (someone or something else)" is from early 14c. In reference to mixing ingredients, etc., by shaking a container from late 14c. Meaning "to rid oneself of by abrupt twists" is from c. 1200, also in Middle English in reference to evading responsibility, etc. Meaning "weaken, impair" is from late 14c., on notion of "make unstable."

To shake hands dates from 1530s. Shake a (loose) leg "hurry up" first recorded 1904; shake a heel (sometimes foot) was an old way to say "to dance" (1660s); to shake (one's) elbow (1620s) meant "to gamble at dice." Phrase more _____ than you can shake a stick at is attested from 1818, American English. To shake (one's) head as a sign of disapproval is recorded from c. 1300.
shake-down (n.): also shakedown, 1730, "impromptu bed made upon loose straw," from verbal phrase; see shake (v.) + down (adv.). Meaning "forced contribution" (1902) is from the verbal phrase in a slang sense "blackmail, extort" (1872). Meaning "a thorough search" is from 1914; perhaps from the notion of measuring corn. The oldest use of the verbal phrase shake down is "cause to totter and fall" (c. 1400).
shake-up (n.): also shakeup, "reorganization," 1899, from verbal phrase, from shake (v.) + up (adv.).
shaken (adj.): of persons, "weakened and agitated by shocks," 1640s, past participle adjective from shake (v.).
shakeout (n.): also shake-out, "business upheaval," 1895, from verbal phrase; see shake (v.) + out (adv.).
shaker (n.): mid-15c., "one who or which shakes," agent noun from shake (v.). Applied from 1640s (with capital initial) to various Christian sects whose devotional exercises often involved convulsions. The best-known, the American-based "Society of Believers in Christ's Second Appearing;" so called from 1784; the adjective with reference to furniture styles associated with these Shakers is recorded from 1866. Meaning "container for mixing cocktails, etc." is recorded from 1868. Phrase movers and shakers is attested from 1874.
Shakespeare: surname recorded from 1248; it means "a spearman." This was a common type of English surname (Shakelance (1275), Shakeshaft (1332)). Shake (v.) in the sense of "to brandish or flourish (a weapon)" is attested from late Old English
Heo scæken on heore honden speren swiðe stronge. [Laymon, "Brut," c. 1205]
Compare also shake-buckler "a swaggerer, a bully;" shake-rag "ragged fellow, tatterdemalion." "Never a name in English nomenclature so simple or so certain in origin. It is exactly what it looks -- Shakespear" [Bardsley, "Dictionary of English and Welsh Surnames," 1901]. Nevertheless, speculation flourishes. The name was variously written in contemporary records, also Shakespear, Shakespere, the last form being the one adopted by the New Shakespere Society of London and the first edition of the OED. Related: Shakespearian (1753); Shakesperean (1796); Shakesperian (1755).
shaking (n.): late 14c., verbal noun from shake (v.).
shako (n.): cylindrical soldier's hat with plume, 1815, from Hungarian csákó, short for csákós süveg "peaked cap," from adjectival form of csáko "peak, projecting point of a cow's horn," which some European etymologists derive from German zacken "point, spike," but which Hungarian sources regard as of unknown origin.
Shakti (n.): from Sanskrit saknoti "is able, is strong," from PIE root *kak- "to enable, help."
shaky (adj.): 1840, of handwriting; 1841 of persons, horses, and credit; 1850 of structures; from shake (v.) + -y (2). General sense of "uncertain, of questionable integrity" is from 1834. Earliest of trees or logs, "split, having fissures" (1808). Related: Shakily; shakiness.
shale (n.): 1747, possibly a specialized use of Middle English schale "shell, husk, pod" (late 14c.), also "fish scale," from Old English scealu (see shell (n.)) in its base sense of "thing that divides or separate," in reference to the way the rock breaks apart in layers. Compare Middle English sheel "to shell, to take off the outer husk" (late 15c.). Geological use also possibly influenced by German Schalstein "laminated limestone," and Schalgebirge "layer of stone in stratified rock."
shall (v.): Old English sceal, Northumbrian scule "I owe/he owes, will have to, ought to, must" (infinitive sculan, past tense sceolde), a common Germanic preterite-present verb (along with can, may, will), from Proto-Germanic *skal- (source also of Old Saxon sculan, Old Frisian skil, Old Norse and Swedish skola, Middle Dutch sullen, Old High German solan, German sollen, Gothic skulan "to owe, be under obligation;" related via past tense form to Old English scyld "guilt," German Schuld "guilt, debt;" also Old Norse Skuld, name of one of the Norns), from PIE root *skel- (2) "to be under an obligation."

Ground sense of the Germanic word probably is "I owe," hence "I ought." The sense shifted in Middle English from a notion of "obligation" to include "futurity." Its past tense form has become should (q.v.). Cognates outside Germanic are Lithuanian skeleti "to be guilty," skilti "to get into debt;" Old Prussian skallisnan "duty," skellants "guilty."
shallop (n.): "kind of light boat," 1570s, from French chaloupe, from Dutch sloep "sloop" (see sloop). Compare Spanish chalupa, Italian scialuppa.
shallot (n.): "small onion," 1660s, shortened from eschalot, from French échalote, from Middle French eschalotte, from Old French eschaloigne, from Vulgar Latin *escalonia (see scallion).
shallow (adj.): c. 1400, schalowe "not deep," probably from or related to Old English sceald (see shoal (n.)). Of breathing, attested from 1875; of thought or feeling, "superficial," first recorded 1580s. The noun, usually shallows, is first recorded 1570s, from the adjective.
shalom: Jewish word of greeting, Hebrew, literally "peace," properly "completeness, soundness, welfare," from stem of shalam "was intact, was complete, was in good health." Related to Arabic salima "was safe," aslama "surrendered, submitted."