Online Etymology Dictionary

solidarity (n.): 1841, from French solidarité "mutual responsibility," a coinage of the "Encyclopédie" (1765), from solidaire "interdependent, complete, entire," from solide (see solid (adj.)). With a capital S-, the name of an independent trade union movement in Poland, formed September 1980 and officially banned October 1982, from Polish Solidarność.
solidary: 1818, from French solidaire, from solide (see solid).
solidification (n.): 1811; noun of action from solidify.
solidify (v.): 1799 (transitive); 1837 (intransitive), from French solidifier, from Old French solide (see solid (adj.)). Related: Solidified; solidifying.
solidity (n.): 1530s, from French solidité or directly from Latin soliditatem, from solidus (see solid (adj.)).
solidus (n.): late 14c., plural solidi, used of both English shilling and Roman gold coin, from Late Latin solidus, an imperial Roman coin (worth about 25 denarii), from nummus solidus, literally "solid coin" (see solid).
solifidian (n.): "one who believes in salvation by faith alone" (based on Luther's translation of Rom. iii:28), 1590s, Reformation coinage from Latin solus "alone" + fides "faith" (see faith).
soliloquize (v.): 1759, from soliloquy + -ize. Related: Soliloquized; soliloquizing.
soliloquy (n.): c.1600, from Late Latin soliloquium "a talking to oneself," from Latin solus "alone" + loqui "speak." First used in translation of Latin "Liber Soliloquiorum," a treatise by Augustine, who is said to have coined the word, on analogy of Greek monologia (see monologue).
solipsism (n.): 1874, coined from Latin solus "alone" + ipse "self." The view or theory that self is the only object of real knowledge or the only thing that is real.
solipsistic (adj.): 1885, from solipsism + -ic.
solitaire (n.): 1716, "solitary person, recluse," from French solitaire, from Latin solitarius (see solitary). Sense of "a precious stone set by itself" is from 1727. Meaning "card game played by one person" is first attested 1746.
solitary (adj.): mid-14c., from Old French solitaire, from Latin solitarius "alone, lonely," from solitas "loneliness, solitude," from solus "alone" (see sole (adj.)).
solitude (n.): late 14c., from Old French solitude "loneliness," from Latin solitudinem (nominative solitudo) "loneliness," from solus "alone" (see sole (adj.)). "Not in common use in English until the 17th c." [OED]
A man can be himself only so long as he is alone; ... if he does not love solitude, he will not love freedom; for it is only when he is alone that he is really free. [Schopenhauer, "The World as Will and Idea," 1818]
solo (n.): 1690s, "piece of music for one voice or instrument," from Italian solo, literally "alone," from Latin solus "alone" (see sole (adj.)). The adjective in English is recorded from 1712; non-musical sense of "alone, unassisted" is attested from 1909. The verb is first attested 1886.
soloist (n.): 1864, from solo + -ist.
Solomon: masc. proper name, Biblical name of David's son, king of Judah and Israel and wisest of all men, from Greek Solomon, from Hebrew Sh'lomoh, from shelomo "peaceful," from shalom "peace." The Arabic form is Suleiman. The common medieval form was Salomon (Vulgate, Tyndale, Douai); Solomon was used in Geneva Bible and KJV. Used allusively for "a wise ruler" since 1550s.
solon (n.): "legislator," 1620s, from Greek Solon, name of early lawgiver of Athens, one of the seven sages. Often (especially in U.S., where it is applied by journalists to Congressmen, township supervisors, etc.) with a tinge of sarcasm.
solstice (n.): mid-13c., from Old French solstice, from Latin solstitium "point at which the sun seems to stand still," from sol "sun" (see sol) + past participle stem of sistere "to come to a stop, make stand still" (see assist).
solubility (n.): 1670s, from soluble + -ity.
soluble (adj.): late 14c., "capable of being dissolved," from Middle French soluble, from Late Latin solubilis "that may be loosened or dissolved," from stem of Latin solvere "loosen, dissolve" (see solve). Meaning "capable of being solved" is attested from 1705.
solum (n.): Latin, "ground, soil," of unknown origin.
solus: Latin, "alone" (see sole (adj.)). Used in stage directions (1590s) and in phrases solus cum sola "alone with an unchaperoned woman" and solus cum solo "all on one's own," both literally "alone with alone."
solute (n.): from Latin solutus, past participle of solvere (see solve).
solution (n.): late 14c., "a solving or being solved," from Old French solucion, from Latin solutionem (nominative solutio) "a loosening or unfastening," also "a solving," from past participle stem of solvere "to loosen, untie, solve, dissolve" (see solve). Meaning "liquid containing a dissolved substance" is first recorded 1590s.
solvation (n.): 1909, noun of action from solvate, from solvent + -ate.
solve (v.): mid-15c., "to disperse, dissipate, loosen," from Latin solvere "to loosen, dissolve, untie," from PIE *se-lu-, from reflexive pronoun *swe- + base *leu- "to loosen, divide, cut apart" (cf. Greek lyein "to loosen, release, untie," Old English -leosan "to lose," leas "loose;" see lose). The meaning "explain, answer" is attested from 1530s; for sense evolution, see solution. Mathematical use is attested from 1737. Related: Solved; solving.
solvency (n.): 1727; see solvent + -cy.
solvent (adj.): 1650s, "able to pay all one owes," from French solvent, from Latin solventem (nominative solvens), present participle of solvere "loosen, dissolve" (see solve). Noun meaning "substance able to dissolve other substances" first recorded 1670s.
solvitur ambulando: an appeal to practical experience for a solution or proof, Latin, literally "(the problem) is solved by walking," originally in reference to the proof by Diogenes the Cynic of the possibility of motion.
soma (n.): name of an intoxicant used in ancient Vedic ritual, prepared from the juice of some plant, from Sanskrit soma, from PIE *seu- "juice," from root *seue- "to take liquid" (see sup (v.2)). In "Brave New World" (1932), the name of a state-dispensed narcotic producing euphoria and hallucination.
Somalia: country named for the indigenous Somali people, whose name is of unknown origin.
somatic (adj.): "pertaining to the body," 1775, from French somatique, from Greek somatikos "of the body," from soma (genitive somatos) "body" (see somato-).
somatization (n.): 1925, from somato- "body," + -ization.
somato-: before vowels somat-, word-forming element meaning "body," from comb. form of Greek soma (genitive somatos) "body," of unknown origin.
somatosensory (adj.): 1952, from somato- "body" + sensory.
somber (adj.): 1760 (earlier sombrous, c.1730), from French sombre "dark, gloomy," from Old French sombre, from Late Latin subumbrare "to shadow," from sub "under" + umbra "shade, shadow," from PIE *andho- "blind, dark" (see umbrage).
sombre (adj.): chiefly British English spelling of somber (q.v.); for spelling, see -re.
sombrero (n.): 1770, from Spanish sombrero "broad-brimmed hat," originally "umbrella or parasol" (1590s), from sombra "shade," from Late Latin subumbrare (see somber).
some (adj.): Old English sum "some," from Proto-Germanic *sumas (cf. Old Saxon, Old Frisian, Old High German sum, Old Norse sumr, Gothic sums), from PIE root *sem- "one, as one" (cf. Sanskrit samah "even, level, similar, identical;" Greek hamo-; see same) For substitution of -o- for -u-, see come.
The word has had greater currency in English than in the other Teutonic languages, in some of which it is now restricted to dialect use, or represented only by derivatives or compounds, as WFris. sommige, somlike, Du. sommige (also somtiids, sommijlen 'sometimes'), LG sömige (G. dial. summige). [OED]
Meaning "remarkable" is attested from 1808, American English colloquial. A possessive form is attested from 1560s, but always was rare. Many combination forms (somewhat, sometime, somewhere) were in Middle English but often written as two words till 17-19c. Somewhen is rare and since 19c. used almost exclusively in combination with more common compounds. Get some "have sexual intercourse" is attested 1899 in a quote attributed to Abe Lincoln from c.1840.
somebody (n.): c.1300, "indeterminate person," from some + body. Meaning "important person" is from 1560s. Somebody else is from 1640s; meaning "romantic rival" is from 1911.
someday (adv.): 1898 as one word, from some + day.
somehow (adv.): 1660s; from some + how. First attested in phrase somehow or other.
someone (pron.): c.1300, sum on; from some + one. Someone else "romantic rival" is from 1914.
someplace (adv.): 1853, from some + place (n.).
somersault (n.): 1520s, from Middle French sombresault, from Old Provençal sobresaut, from sobre "over" (from Latin supra "over") + saut "a jump," from Latin saltus, from the root of salire "to leap" (see salient). Sometimes further corrupted to somerset, etc.
something (pron.): Old English sum þinge; see some + thing. Hyphenated from c.1300; one word from 17c. Formerly common as an adverb (e.g. something like).
sometime (adv.): mid-14c., "at one time or another" (adv.); as an adv., late 15c. Meaning "at some future time" is late 14c. From some + time (n.). Sometimes "now and then" is from 1520s.
somewhat (adv.): c.1200, "a certain amount, to a certain degree," from some + what. Replaced Old English sumdæl, sume dæle "somewhat, some portion," literally "some deal."
somewhere (adv.): c.1200, from some + where.