Online Etymology Dictionary

sago (n.): "starch made of the piths of palms," 1550s, via Portuguese and Dutch from Malay sagu, the name of the palm tree from which it is obtained.
saguaro (n.): type of large branching cactus of the North American desert, 1856, from Mexican Spanish, from Piman native name, of unknown origin.
Sahara: 1610s, from Arabic çahra "desert" (plural çahara), according to Klein, noun use of fem. of the adjective asharu "yellowish red."
Sahel: from Arabic sahil "sea coast, shore."
sahib: respectful address to Europeans in India, 1670s, from Hindi or Urdu sahib "master, lord," from Arabic, originally "friend, companion," from sahiba "he accompanied."
said: past tense of say (q.v.).
Saigon: Vietnamese city, named for its river, which bears a name of uncertain origin.
sail (n.): Old English segl, from Proto-Germanic *seglom (cf. Swedish segel, Old Norse segl, Old Frisian seil, Dutch zeil, Old High German segal, German Segel), of obscure origin with no known cognates outside Germanic. Irish seol, Welsh hwyl "sail" are Germanic loan-words. Sometimes referred to PIE root *sek- "to cut," as if meaning "a cut piece of cloth."
sail (v.): Old English segilan, from the same Germanic source as sail (n.); cognate with Old Norse sigla, Middle Low German segelen, German segeln. Related: Sailed; sailing.
sailboat (n.): 1798, from sail (n.) + boat (n.).
sailor (n.): c.1400, sailer, agent noun from sail (v.). Spelling with -o- emerged c.1500, probably by influence of tailor, etc., to distinguish the meaning "seaman, mariner" from "thing that sails." It replaced much older seaman and mariner (q.q.v.). Old English also had merefara "sailor."
sain (v.): "to cross oneself; to mark with the sign of the cross," Old English segnian, from Latin signare "to sign" (in Church Latin "to make the sign of the Cross"); see sign (n.). A common Germanic borrowing, cf. Old Saxon segnon, Dutch zegenen, Old High German seganon, German segnen "to bless," Old Norse signa.
saint (n.): early 12c., from Old French seinte, altering Old English sanct, both from Latin sanctus "holy, consecrated" (used as a noun in Late Latin), prop. past participle of sancire "consecrate" (see sacred). Adopted into most Germanic languages (cf. Old Frisian sankt, Dutch sint, German Sanct). Originally an adjective prefixed to the name of a canonized person; by c.1300 it came to be regarded as a noun.
Saint, n. A dead sinner revised and edited. The Duchess of Orleans relates that the irreverent old calumniator, Marshal Villeroi, who in his youth had known St. Francis de Sales, said, on hearing him called saint: 'I am delighted to hear that Monsieur de Sales is a saint. He was fond of saying indelicate things, and used to cheat at cards. In other respects he was a perfect gentleman, though a fool.' [Ambrose Bierce, "Devil's Dictionary," 1911]
Meaning "person of extraordinary holiness" is recorded from 1563. The verb meaning "to enroll (someone) among the saints" is attested from late 14c. Applied widely to living things, diseases, objects and phenomena, e.g. Saint Bernard, the breed of mastiff dogs (1839), so called because they were used by the monks of the hospice of the pass of St. Bernard (between Italy and Switzerland) to rescue snowbound travelers; St. Elmo's Fire "corposant" (1560s) is from Italian fuoco di Sant'Elmo, named for the patron saint of Mediterranean sailors, a corruption of the name of St. Erasmus, an Italian bishop martyred in 303.
sake (n.2): "Japanese rice liquor," 1680s, from Japanese sake, literally "alcohol."
sake (n.1): "purpose," Old English sacu "a cause at law, crime, dispute, guilt," from Proto-Germanic *sako "affair, thing, charge, accusation" (cf. Old Norse sök "charge, lawsuit, effect, cause," Old Frisian seke "strife, dispute, matter, thing," Dutch zaak, German sache "thing, matter, affair, cause"), from PIE root *sag- "to investigate" (cf. Old English secan, Gothic sokjan "to seek;" see seek).

Much of the word's original meaning has been taken over by case, cause, and it survives largely in phrases for the sake of (early 13c.) and for _______'s sake (c.1300, originally for God's sake), both probably are from Norse, as these forms have not been found in Old English.
saki (n.): see sake.
sakura: 1884, from Japanese.
sal (n.): chemical name for salt, late 14c., from Old French sal, from Latin sal (genitive salis) "salt" (see salt (n.)). For sal ammoniac "ammonium chloride" (early 14c.), see ammonia.
sal volatile (n.): 1650s, Modern Latin, literally "volatile salt" (see salt (n.) + volatile); ammonium carbonate, especially as used in reviving persons who have fainted.
salaam: Muslim greeting, 1610s, from Arabic salam (also in Urdu, Persian), literally "peace" (cf. Hebrew shalom); in full, (as)salam 'alaikum "peace be upon you," from base of salima "he was safe" (cf. Islam, Muslim).
salacious (adj.): 1660s, from Latin salax (genitive salacis) "lustful," probably originally "fond of leaping," as in a male animal leaping on a female in sexual advances, from salire "to leap" (see salient). Earliest form of the word in English is salacity (c.1600).
salad (n.): late 14c., from Old French salade (14c.), from Vulgar Latin *salata, literally "salted," short for herba salata "salted vegetables" (vegetables seasoned with brine, a popular Roman dish), from fem. past participle of *salare "to salt," from Latin sal (genitive salis) "salt" (see salt (n.)).

Dutch salade, German Salat, Swedish salat, Russian salat are from Romanic languages. Salad days, "time of youthful inexperience" (on notion of "green") is first recorded 1606 in Shakespeare. Salad bar first attested 1940, American English.
Saladin: Sultan of Egypt and Syria 1174-93, in full Salah-ad-din Yusuf ibn-Ayyub (1137-1193).
salamander (n.): mid-14c., "legendary lizard-like creature that can live in fire," from Old French salamandre (12c.), from Latin salamandra, from Greek salamandra, probably of eastern origin. The application to an actual amphibian is first recorded 1610s.

Aristotle, and especially Pliny, are responsible for the fiction of an animal that thrives in and extinguishes fires. The amphibian lives in damp logs and secretes a milky substance when threatened, but there is no obvious natural explanation its connection with the myth. Also used 18c. for "a woman who lives chastely in the midst of temptations" (after Addison), and "a soldier who exposes himself to fire in battle." To rub someone a salamander was a 19c. form of German student drinking toast (einem einen salamander reiben).
salami (n.): "salted, flavored Italian sausage," 1852, from Italian salami, plural of salame "spiced pork sausage," from Vulgar Latin *salamen, from *salare "to salt," from Latin sal (genitive salis) "salt" (see salt (n.)).
salary (n.): mid-14c., "compensation, payment," whether periodical, for regular service or for a specific service; from Anglo-French salarie (late 13c.), Old French salarie, from Latin salarium "salary, stipend," originally "soldier's allowance for the purchase of salt," noun use of neuter of adjective salarius "pertaining to salt," from sal (genitive salis) "salt" (see salt (n.)). Japanese sarariman "male salaried worker," literally "salary-man," is from English. The verb meaning "to pay a regular salary to" is attested from late 15c.
salat: Islamic ritual prayer, from Arabic salah "prayer."
sale (n.): late Old English sala "a sale," from Old Norse sala "sale," from Proto-Germanic *salo (cf. Old High German sala, Swedish salu, Danish salg), from root *sal-, source of *saljan (cf. Old English sellan; see sell (v.)). Sense of "a selling of shop goods at lower prices than usual" first appeared 1866. Sales tax attested by 1886. Sales associate by 1946.
saleable (adj.): also salable, 1520s, from sale + -able. Related: Salability; saleability.
Salem: place mentioned in Gen. xiv:18, from Hebrew Shalem, usually said to be another word for Jerusalem and to mean "peace" (cf. Hebrew shalom, Arabic salaam). So common as a Baptist and Methodist meetinghouse name that by mid-19c. it (along with Bethel and Ebenezer) had come to be used in Britain generically to mean "non-conformist chapel."
salep (n.): 1736 (also saloop, 1712) "a starch or jelly made from dried tubers of orchid-like plants, formerly used as a drug," from Turk. salep, from dialectal pronunciation of Arabic thaeleb, which usually is taken to be a shortening of khasyu 'th-thaeleb, literally "fox's testicles" (cf. native English name dogstones).
salesman (n.): 1520s, from genitive of sale (cf. craftsman, tradesman) + man (n.).
salesmanship (n.): 1880, from salesman + -ship.
salesperson (n.): 1920, from genitive of sale + person.
saleswoman (n.): 1794, from genitive of sale + woman.
Salic (adj.): 1540s, from French Salique, from Medieval Latin Salicus, from the Salian Franks, a tribe that once lived near the Zuider Zee, the ancestors of the Merovingian kings, literally "those living near the river Sala" (modern Ijssel). Salic Law, code of law of Germanic tribes, was invoked 1316 by Philip V of France to exclude a woman from succeeding to the throne of France (and later to combate the French claims of Edward III of England), but the precise meaning of the passage is unclear.
salience (n.): 1836, "quality of leaping;" see salient + -ence. Meaning "quality of standing out" is from 1849. It was used in Middle English as an adjective meaning "leaping, skipping."
saliency (n.): 1660s; see salient + -cy.
salient (adj.): 1560s, "leaping," a heraldic term, from Latin salientem (nominative saliens), present participle of salire "to leap," from PIE root *sel- "to jump" (cf. Greek hallesthai "to leap," Middle Irish saltraim "I trample," and probably Sanskrit ucchalati "rises quickly").

The meaning "pointing outward" (preserved in military usage) is from 1680s; that of "prominent, striking" first recorded 1840, from salient point (1670s), which refers to the heart of an embryo, which seems to leap, and translates Latin punctum saliens, going back to Aristotle's writings. Hence, the "starting point" of anything.
saline (adj.): "made of salt," c.1500, probably from a Latin word related to salinum "salt cellar" and salinae "salt pits," from sal (genitive salis) "salt" (see salt). Also in Middle English as a noun meaning "salt pit." Related: Salination.
salinity (n.): 1650s; see saline + -ity.
Salisbury steak (n.): 1897, from J.H. Salisbury (1823-1905), U.S. physician and food specialist, who promoted it. Incorrect use for "hamburger" traces to World War I and the deliberate attempt to purify American English of German loan words.
saliva (n.): early 15c., from Middle French salive, from Latin saliva "spittle," of unknown origin (perhaps, as Tucker suggests, somehow derived from the base of sallow (adj.)).
salivary (adj.): 1709, from Latin salivarius, from saliva (see saliva).
salivate (v.): 1660s, from Latin salivatus, past participle of salivare, from saliva (see saliva). Related: Salivated; salivating.
Salk: in reference to vaccine against poliomyelitis, 1954, from U.S. virologist Jonas Edward Salk (1914-1995), who developed it.
sallow (n.): "shrubby willow plant," Old English sealh (Anglian salh), from Proto-Germanic *salhjon (cf. Old Norse selja, Old High German salaha, and first element in German compound Salweide), from PIE *sal(i)k- "willow" (cf. Latin salix "willow," Middle Irish sail, Welsh helygen, Breton halegen "willow"). French saule "willow" is from Frankish salha, from the Germanic root. Used in Palm Sunday processions and decorations in England before the importing of real palm leaves began.
sallow (adj.): Old English salo "dusky, dark" (related to sol "dark, dirty"), from Proto-Germanic *salwa- (cf. Middle Dutch salu "discolored, dirty," Old High German salo "dirty gray," Old Norse sölr "dirty yellow"), from PIE root *sal- "dirty, gray" (cf. Old Church Slavonic slavojocije "grayish-blue color," Russian solovoj "cream-colored").
Sally: fem. proper name, alteration of Sarah (cf. Hal from Harry, Moll from Mary, etc.). Sally Lunn cakes (1780) supposedly named for the woman in Bath who first made them. Sally Ann as a nickname for Salvation Army is recorded from 1927.
sally: 1540s (n.), 1550 (v.), from Middle French saillie "a rushing forth," noun use of fem. past participle of saillir "to leap," from Latin salire "to leap" (see salient). Related: Sallied; sallying.