Online Etymology Dictionary

snag (n.): 1570s, "stump of a tree, branch," of Scandinavian origin, cf. Old Norse snagi "clothes peg," snaga "a kind of ax." The meaning "sharp or jagged projection" is first recorded 1580s; that of "obstacle, impediment" is 1829. Snaggle-toothed "having crooked, projecting teeth" (1580s) is from the same root.
snag (v.): "to be caught on an impediment," 1807, from snag (n.). Originally in American English, often in reference to steamboats caught on branches and stumps lodged in riverbeds. The meaning "to catch, steal, pick up" is U.S. colloquial, attested from 1895. Related: Snagged; snagging.
snail (n.): Old English snægl, from Proto-Germanic *snagilas (cf. Old Saxon snegil, Old Norse snigill, Middle High German snegel, dialectal German Schnegel, Old High German snecko, German Schnecke "snail"), from root *snag-, *sneg- "to crawl" (see snake (n.)). The word essentially is a diminutive form of Old English snaca "snake," literally "creeping thing." Also formerly used of slugs. Symbolic of slowness since at least c.1000; snail's pace is attested from c.1400.
snake (n.): Old English snaca, from Proto-Germanic *snakon (cf. Old Norse snakr "snake," Swedish snok, German Schnake "ring snake"), from PIE root *snag-, *sneg- "to crawl, creeping thing" (cf. Old Irish snaighim "to creep," Lithuanian snake "snail," Old High German snahhan "to creep"). In Modern English, gradually replacing serpent in popular use. Meaning "treacherous person" first recorded 1590 (cf. Old Church Slavonic gadu "reptile," gadinu "foul, hateful").

Snake eyes in crap-shooting sense is from 1929. Snake oil is from 1927. Snake-bitten "unlucky" is sports slang from 1957. The game of Snakes and Ladders is attested from 1907. Snake pit is from 1883, as a supposed primitive test of truth or courage; figurative sense is from 1941. Phrase snake in the grass is from Virgil's Latet anguis in herba [Ecl. III:93] Another Old English word for "snake" was næddre (see adder).
snake (v.): 1650s, "to twist or wind (something) into the form of a snake," from snake (n.). The intransitive sense of "to move like a snake" is attested from 1848; that of "to wind or twist like a snake" (of roads, etc.) is from 1875. Related: Snaked; snaking.
snap (n.): late 15c., "quick, sudden bite or cut," from Dutch or Low German snappen "to snap," probably related to Middle Low German or Middle Dutch snavel "bill, beak" (see nib). Sense of "quick movement" is first recorded 1630s; that of "something easily done" is 1877. Common in compounds to indicate instantaneous action (cf. cold snap, 1829). The card game is attested from 1882. Snap judgment is attested from 1841.
snap (v.): 1520s, "to make a quick bite" (of animals), from snap (n.). Meaning "to break suddenly or sharply" is first recorded c.1600; the mental sense is from 1970s. U.S. football sense first recorded 1887. Related: Snapped; snapping. To snap the fingers is from 1670s. Phrase snap out of it recorded by 1907. Snapping turtle is attested from 1784. Snap-brim as a type of hat is from 1928.
snapdragon (n.): 1570s, from snap + dragon. So called from fancied resemblance of antirrhinum flowers to a dragon's mouth.
snape (v.): "to be hard upon, rebuke, snub," c.1300, from Old Norse sneypa "to outrage, dishonor, disgrace." Snaiping "rebuking, reproaching, reviling" is attested from early 14c.
snapper (n.): applied to various fishes since 1690s, agent noun from snap (v.). Slang meaning "vagina" is by 2000. As a short form of snapping turtle it is recorded from 1872. Snappers "teeth" is attested from 1924.
snappish (adj.): "peevish," 1540s, from snap (v.) + -ish. Related: Snappishly; snappishness.
snappy (adj.): "quick, energetic," 1831, from snap + -y (2). Related: Snappily; snappiness.
snapshot (n.): also snap-shot, 1808, "a quick shot with a gun, without aim, at a fast-moving target," from snap + shot (n.). Photographic sense is attested from 1890.
snare (n.1): "noose for catching animals," c.1100, from Old Norse snara "noose, snare," related to soenri "twisted rope," from Proto-Germanic *snarkho (cf. Middle Dutch snare, Dutch snaar, Old High German snare, German Schnur "noose, cord").
snare (n.2): "string across a drum," 1680s, probably from Dutch snaar "string," from same source as snare (n.1).
snare (v.): late 14c., "to ensnare," from snare (n.1). Related: Snared; snaring.
snarf (v.): "to take, grab," by 1989. Related: Snarfed; snarfing.
snark (n.): imaginary animal, coined 1876 by Lewis Carroll in "The Hunting of the Snark." In 1950s, name of a type of U.S. cruise missile and in 1980s of a type of sailboat. Meaning "caustic, opinionated, critical rhetoric" is from c.2002 (see snarky).
snarky (adj.): "irritable, short-tempered," 1906, from snark (v.) "to snort" (1866), from an imitative source akin to Low German snarken, North Frisian snarke, Swedish snarka.
snarl (v.2): "growl and bare the teeth," 1520s, perhaps from Dutch or Low German snarren "to rattle," probably of imitative origin (cf. German schnarren "to rattle," schnurren "to hum, buzz"). Meaning "speak in a harsh manner" first recorded 1690s. Related: Snarled; snarling.
snarl (v.1): "to tangle, to catch in a snare or noose," late 14c., from a noun snarl "a snare, a noose" (late 14c.), probably a diminutive of snare (n.1). The noun meaning "a tangle, a knot" is first attested c.1600. Related: Snarled; snarling.
snatch (n.): c.1300, "a trap, snare," from snatch (v.). Vulgar slang sense of "vulva" is recorded from 1903; from a much older sense of "sexual intercourse quickly performed" (1580s).
snatch (v.): early 13c., of uncertain origin; perhaps from an unrecorded Old English *snæccan or Middle Dutch snacken "to snatch, chatter." Weight-lifting sense is attested from 1928. Related: Snatched; snatching.
snazzy (adj.): "stylish, flashy," 1932, U.S. colloquial, perhaps a blend of snappy and jazzy.
SNCC: 1960, initialism from Student Nonviolent Coordinating Committee, which was organized in 1960.
SNCF: French national railway, 1949, initialism for Société Nationale des Chemins de Fer.
sneak (v.): 1560 (implied in sneakish), perhaps from some dialectal survival of Middle English sniken "to creep, crawl," related to Old English snican "to desire, reach for sneakily," from Proto-Germanic *sneikanan, which is related to the root of snake (q.v.). Sneak-thief first recorded 1859; sneak-preview is from 1938.
sneak (n.): "a sneaking person," 1640s, from sneak (v.).
sneaker (n.): 1590s, "one who sneaks," agent noun from sneak (v.). Meaning "rubber-soled shoe" is attested from 1895, American English; earlier sneak (1862), so called because the shoe was noiseless. See also plimsoll.
The night-officer is generally accustomed to wear a species of India-rubber shoes or goloshes on her feet. These are termed 'sneaks' by the women [of Brixton Prison]. ["Female Life in Prison," 1862]
sneaky (adj.): 1833, from sneak + -y (2). Related: Sneakily; sneakiness. Sneaky Pete "cheap liquor" is from 1949.
sneer (v.): 1550s, "to snort" (of horses), perhaps from North Frisian sneere "to scorn," related to Old English fnæran "to snort, gnash one's teeth," of imitative origin (cf. Danish snærre "to grin like a dog," Middle Dutch, Middle High German snarren "to rattle"). Meaning "to smile contemptuously" is from 1670s; sense of "to curl the upper lip in scorn" is attested from 1775. Related: Sneered; sneering.
sneer (n.): 1707, from sneer (v.).
sneeze (v.): Old English fneosan "to snort, sneeze," from Proto-Germanic *fneusanan (cf. Middle Dutch fniesen, Dutch fniezen "to sneeze;" Old Norse fnysa "to snort;" Old Norse hnjosa, Swedish nysa "to sneeze;" Old High German niosan, German niesen "to sneeze"), from Proto-Germanic base *fneu-s- "sneeze," of imitative origin, as is PIE *pneu- "to breathe" (cf. Greek pnein "to breathe").

Other imitative words for it, perhaps in various ways related to each other, include Latin sternuere (cf. Italian starnutare, French éternuer, Spanish estornudar), Breton strevia, Sanskrit ksu-, Lithuanian čiaudeti, Polish kichać, Russian čichat'. English forms in sn- appear late 15c.; change may be due to a misreading of fn-, or from Norse influence. But OED suggests Middle English fnese had been reduced to simple nese by early 15c., and sneeze is a "strengthened form" of this, "assisted by its phonetic appropriateness." Related: Sneezed; sneezing. To sneeze at "to regard as of little value" (usually with negative) is attested from 1806.
sneeze (n.): 1640s, from sneeze (v.).
snick (n.): 1962, American English, from common pronunciation of SNCC, initialism for "Student Non-violent Co-ordinating Committee," black civil rights organization.
snicker (v.): 1690s, possibly of imitative origin, similar to Dutch snikken "to gasp, sob." Related: Snickered; snickering. The noun is first recorded 1836, from the verb.
snickersnee (n.): 1690s, originally "fight with knives," from snick-or-snee (1610s), from Dutch steken "to thrust, stick" + snijden "to cut" (cf. German schneiden).
snide (adj.): 1859, thieves' slang "counterfeit, sham," of unknown origin. Of persons, "cunning, sharp," from 1883. Sense of "sneering" is first attested 1933.
sniff (v.): mid-14c., of imitative origin; possibly related to snyvelen (see snivel). As a synonym for smell (v.) it dates from 1845. In reference to cocaine from 1925. Related: Sniffed; sniffing. The noun is first recorded 1767; the scornful sense is from 1859.
sniffle (v.): 1819, frequentative form of sniff. Related: Sniffled; sniffling. The sniffles "runny nose, head cold" is recorded from 1825.
snifter (n.): 1844, "a drink of liquor," earlier "a sniff," from an obsolete verb meaning "to sniff, snivel" (mid-14c.), of imitative origin. Meaning "large bulbous stemmed glass for drinking brandy" is from 1937. The association of "drinking liquor" with words for "inhaling, snuffling" (e.g. snort) is perhaps borrowed from snuff-taking and the nasal reaction to it.
snigger (v.): 1706, variant form of snicker (v.). Related: Sniggered; sniggering.
sniggler (n.): 1840, in reference to fishing (especially for eels), agent noun from sniggle (v.) attested in this sense from 1670s.
snip (n.): 1550s, "small piece of cut-out cloth," probably from Dutch or Low German snippen "to snip, shred," of imitative origin. Snip-snap-snorum, the card game, is 1755, from Low German.
snip (v.): 1580s, from snip (n.). Related: Snipped; snipping.
snipe (v.): "shoot from a hidden place," 1773 (among British soldiers in India), in reference to hunting snipe as game, from snipe (n.). Related: Sniped; sniping.
snipe (n.): long-billed marsh bird, early 14c., from Old Norse -snipa in myrisnipa "moor snipe;" perhaps a common Germanic term (cf. Old Saxon sneppa, Middle Dutch snippe, Dutch snip, Old High German snepfa, German Schnepfe "snipe"). The Old English name was snite, which is of uncertain derivation. An opprobrious term (cf. guttersnipe) since c.1600.
sniper (n.): "sharpshooter; one who shoots from a hidden place," 1824, agent noun from snipe (v.). The birds were considered a challenging target for an expert shooter:
Snipe Shooting is a good trial of the gunner's skill, who often engages in this diversion, without the assistance of a dog of any kind; a steady pointer, however, is a good companion. ["Sportsman's Calendar," London, December 1818]
snippers (n.): "scissors," 1590s, plural agent noun from snip (v.).
snippet (n.): 1660s, diminutive form of snip (n.).