serpentine (n.) Look up serpentine at Dictionary.com
c.1400, "plant reputed to contain antivenom," from Old French serpentin name of a precious stone, noun use of adjective meaning "of a snake, snake-like; sly, deceptive," from Late Latin serpentius "of a serpent," from Latin serpentem (nominative serpens) "snake" (see serpent). As the name of a greenish igneous rock consisting mainly of hydrous magnesium silicate, attested from early 15c.
serpentine (adj.) Look up serpentine at Dictionary.com
"twisting, winding," 1610s; see serpent + -ine (1). An earlier adjective meaning "having the evil qualities of a serpent" is recorded from late 14c., from the French source of serpentine (n.). The winding lake of that name in Hyde Park, London, was constructed in 1730.
serrate (adj.) Look up serrate at Dictionary.com
"notched," 1660s, from Latin serratus "sawlike, notched like a saw," from serra "a saw," of unknown origin. Related: Serrated; serrating.
serrated (adj.) Look up serrated at Dictionary.com
1703, past participle adjective based on Latin serratus (see serrate (adj.)). Serrating "sawing" attested from 1590s, but serrate as a transitive verb not attested before 1750 according to OED.
serration (n.) Look up serration at Dictionary.com
"condition of being serrated," 1808, noun of state from serrate (adj.).
serried (adj.) Look up serried at Dictionary.com
"pressed close together," 1667 (in "Paradise Lost"), probably a past participle adjective from serry "to press close together" (1580s), a military term, from Middle French serre "close, compact" (12c.), past participle of serrer "press close, fasten," from Vulgar Latin *serrare "to bolt, lock up," from Latin serare, from sera "a bolt, bar, cross-bar," perhaps from PIE *ser- (3) "to line up" (see series). Modern use is due to the popularity of Scott, who used it with phalanx.
serum (n.) Look up serum at Dictionary.com
1670s, "watery animal fluid," from Latin serum "watery fluid, whey," from PIE root *ser- (2) "to run, flow" (cognates: Greek oros "whey;" Sanskrit sarah "flowing," sarit "brook, river"). First applied 1893 to blood serum used in medical treatments.
serval (n.) Look up serval at Dictionary.com
African wild cat, 1771, from Modern Latin serval, French serval (Buffon, 1765), from Portuguese (lobo) cerval "lynx," from Latin lupus cervarius (source of French loup cervier) "lynx," literally "wolf that hunts the stag," from cervarius "pertaining to a stag," from cervus "stag," from PIE *ker-wo- "having horns," suffixed form of root *ker- (1) "horn, head" (see horn (n.)).
servant (n.) Look up servant at Dictionary.com
c.1200, "personal or domestic attendant," from Old French servant "servant; foot-soldier," noun use of servant "serving, waiting," present participle of servir "to attend, wait upon" (see serve (v.)).

Meaning "professed lover, one devoted to the service of a lady" is from mid-14c. In North American colonies and U.S., the usual designation for "slave" 17c.-18c. (in 14c.-15c. and later in Biblical translations the word often was used to render Latin servus, Greek doulos "slave"). Public servant is attested from 1670s.
serve (v.) Look up serve at Dictionary.com
late 12c., "to render habitual obedience to," also "minister, give aid, give help," from Old French servir "to do duty toward, show devotion to; set table, serve at table; offer, provide with," from Latin servire "be a servant, be in service, be enslaved;" figuratively "be devoted; be governed by; comply with; conform; flatter," originally "be a slave," related to servus "slave," perhaps from Etruscan (compare Etruscan proper names Servi, Serve, Latinized as Servius).

By c.1200 also as "to be in the service of, perform a service for; attend upon, be personal servant to; be a slave; owe allegiance to; officiate at Mass or other religious rites;" from early 13c. as "set food at table;" mid-14c. as "to wait on (customers)." From late 14c. as "treat (someone or something) in some fashion." To serve (someone) right "to treat as he deserves" is recorded from 1580s.
He no schuld neuer wond
To seruen him fro fot to hond
["Amis and Amiloun," c.1330]
Sense of "be useful, be beneficial, be suitable for a purpose or function" is from early 14c.; that of "take the place or meet the needs of, be equal to the task" is from late 14c.; that of "suffice" is from mid-15c. Meaning "render active military service" is from 1510s. Sporting sense, in tennis, badminton, etc., first recorded 1580s. Legal sense "present" (a writ, warrant,etc.), "give legal notice of" is from early 15c.
serve (n.) Look up serve at Dictionary.com
1680s, in sports (tennis, etc.), from serve (v.).
served (adj.) Look up served at Dictionary.com
"found guilty, convicted; ordered to be punished or transported; beaten," 1811, slang past participle adjective from serve (v.).
server (n.) Look up server at Dictionary.com
late 14c., agent noun from serve (v.). Computer sense by 1992.
servery (n.) Look up servery at Dictionary.com
1893, from serve + -ery.
Servian Look up Servian at Dictionary.com
1754 (n.), 1723 (adj.), from Medieval Latin Servia, from Serb Serb (see Serb).
service (n.1) Look up service at Dictionary.com
c.1100, "celebration of public worship," from Old French servise "act of homage; servitude; service at table; Mass, church ceremony," from Latin servitium "slavery, condition of a slave, servitude," also "slaves collectively," from servus "slave" (see serve (v.)).

Meaning "act of serving, occupation of an attendant servant" is attested from c.1200, as is that of "assistance, help; a helpful act." From c.1300 as "provision of food; sequence of dishes served in a meal;" from late 14c. as "service at table, attendance during a meal." Meaning "the furniture of the table" (tea service, etc.) is from mid-15c.

Meanings "state of being bound to undertake tasks for someone or at someone's direction; labor performed or undertaken for another" are mid-13c. Sense of "service or employment in a court or administration" is from c.1300, as is that of "military service (especially by a knight); employment as a soldier;" hence "the military as an occupation" (1706).

Also in Middle English "sexual intercourse, conjugal relations" (mid-15c.; service of Venus, or flesh's service). Service industry (as distinct from production) attested from 1938. A service station originally was a gas stop that also repaired cars.
service (v.) Look up service at Dictionary.com
1893, "to provide with service," from service (n.1). Meaning "perform work on" first recorded 1926. Related: Serviced; servicing.
service (n.2) Look up service at Dictionary.com
type of tree or berry, extended form of serve (perhaps via Middle English plural serves being taken as a singular), from Old English syrfe, Old French sorbe, both from Vulgar Latin *sorbea, from Latin sorbus (see sorb).
serviceable (adj.) Look up serviceable at Dictionary.com
"ready to do service," early 14c., from Old French servicable, from servise (see service (n.1)). Related: Serviceability.
Edgar: I know thee well: a serviceable villain,
As duteous to the vices of thy mistress
As badness would desire.
["King Lear," IV.vi.]
serviceman (n.) Look up serviceman at Dictionary.com
1899, from service (n.) + man (n.).
servient (adj.) Look up servient at Dictionary.com
1640s, from Latin servientem "subordinate," present participle of servire "be a servant, be a slave" (see serve (v.)).
serviette (n.) Look up serviette at Dictionary.com
"table napkin," late 15c., from Middle French serviette "napkin, towel" (14c.), of uncertain origin, perhaps from past participle of servir "to serve" (see serve (v.)). Primarily Scottish at first; re-introduced from French 1818.
servile (adj.) Look up servile at Dictionary.com
late 14c., from Latin servilis "of a slave" (as in Servile Wars, name given to the slave revolts in the late Roman Republic), also "slavish, servile," from servus "slave" (see serve (v.)). Earliest sense was legal, servile work being forbidden on the Sabbath; sense of "cringing, fawning" first recorded c.1600.
servility (n.) Look up servility at Dictionary.com
1570s; see servile + -ity.
serving (n.) Look up serving at Dictionary.com
"action of serving," c.1200, verbal noun from serve (v.). As "a helping of food" from 1769.
servitude (n.) Look up servitude at Dictionary.com
early 15c., "condition of being enslaved," from Old French servitude, servitute (13c.) and directly from Late Latin servitudo "slavery," from Latin servus "a slave" (see serve (v.)) + abstract noun suffix.
servo Look up servo at Dictionary.com
1910, from servo-motor (1889), from French servo-moteur (1873), ultimately from Latin servus "slave" (see serve (v.)) + motor "mover" (see motor (n.)).
sesame (n.) Look up sesame at Dictionary.com
early 15c., probably from Middle French sisame and directly from Latin sesamum (nominative sesama), from Greek sesamon (Doric sasamon) "seed or fruit of the sesame plant," a very early borrowing via Phoenician from Late Babylonian *shawash-shammu (compare Assyrian shamash-shammu "sesame," literally "oil-seed"). First as a magic password in 1785 translation of Galland's "Mille et une nuits," where it opens the door of the thieves' den in "Ali Baba and the Forty Thieves." Phrase open sesame current since about 1826.
sesqui- Look up sesqui- at Dictionary.com
word-forming element, from Latin sesqui- "one-half more," contraction of *semis-que- "a half in addition," from semis "a half" (see semi-) + -que "and," from PIE *kwe-.
sesquicentennial (adj.) Look up sesquicentennial at Dictionary.com
"pertaining to a century and a half," 1878, from sesqui- + centennial. As a noun from 1880; first recorded reference is to Baltimore's.
sesquipedalian (n.) Look up sesquipedalian at Dictionary.com
1610s, "person or thing a foot and a half long," from Latin sesquipedalia "a foot-and-a-half long," from sesqui- "half as much again" (see sesqui-) + stem of pes "foot" (see foot (n.)). As an adjective 1650s.

Meaning "sesquipedalian word" (1830) is from Latin sesquipedalia verba "words a foot-and-a-half long," in Horace's "Ars Poetica" (97), nicely illustrating the thing he is criticizing.
sessile (adj.) Look up sessile at Dictionary.com
1725, "adhering close to the surface," from Latin sessilis "pertaining to sitting, for sitting on," from sessum, past participle of sedere "to sit" (see sedentary). In botany from 1753. Meaning "sedentary" first recorded 1860.
session (n.) Look up session at Dictionary.com
late 14c., "periodical sitting of a court," from Old French session "act or state of sitting; assembly," from Latin sessionem (nominative sessio) "act of sitting; a seat; loitering; a session," noun of action from past participle stem of sedere "to sit" (see sedentary). Sense of "period set aside for some activity" is first recorded 1920, in bull session, probably from quarter sessions courts (see quarter (n.)). Musical sense of "recording occasion in a studio" is from 1927.
sestet (n.) Look up sestet at Dictionary.com
1801, from Italian sestetto, diminutive of sesto "sixth," from Latin sextus (see Sextus).
sestina (n.) Look up sestina at Dictionary.com
1797, from Italian, "poem of six-lined stanzas," from sesto "sixth," from Latin sextus (see six). Invented by 12c. Provençal troubadour Arnaut Daniel. The line endings of the first stanza are repeated in different order in the rest, and in an envoi.
set (v.) Look up set at Dictionary.com
Old English settan (transitive) "cause to sit, put in some place, fix firmly; build, found; appoint, assign," from Proto-Germanic *(bi)satjan "to cause to sit, set" (cognates: Old Norse setja, Swedish sätta, Old Saxon settian, Old Frisian setta, Dutch zetten, German setzen, Gothic satjan), causative form of PIE *sod-, variant of *sed- (1) "to sit" (see sit (v.)). Also see set (n.2).

Intransitive sense from c.1200, "be seated." Used in many disparate senses by Middle English; sense of "make or cause to do, act, or be; start" and that of "mount a gemstone" attested by mid-13c. Confused with sit since early 14c. Of the sun, moon, etc., "to go down," recorded from c.1300, perhaps from similar use of the cognates in Scandinavian languages. To set (something) on "incite to attack" (c.1300) originally was in reference to hounds and game.
set (adj.) Look up set at Dictionary.com
"fixed," c.1200, sett, past participle of setten "to set" (see set (v.)). Meaning "ready, prepared" first recorded 1844.
set (n.1) Look up set at Dictionary.com
"collection of things," mid-15c., from Old French sette "sequence," variant of secte "religious community," from Medieval Latin secta "retinue," from Latin secta "a following" (see sect). "[I]n subsequent developments of meaning influenced by SET v.1 and apprehended as equivalent to 'number set together'" [OED]. The noun set was in Middle English, but only in the sense of "religious sect" (late 14c.), which likely is the direct source of some modern meanings, such as "group of persons with shared status, habits, etc." (1680s).

Meaning "complete collection of pieces" is from 1680s. Meaning "group of pieces musicians perform at a club during 45 minutes" (more or less) is from c.1925, though it is found in a similar sense in 1580s. Set piece is from 1846 as "grouping of people in a work of visual art;" from 1932 in reference to literary works.
set (n.2) Look up set at Dictionary.com
"act of setting; condition of being set" (of a heavenly body), mid-14c., from set (v.) or its identical past participle. Many disparate senses collect under this word because of the far-flung meanings assigned to the verb:

"Action of hardening," 1837; also "manner or position in which something is set" (1530s), hence "general movement, direction, tendency" (1560s); "build, form" (1610s), hence "bearing, carriage" (1855); "action of fixing the hair in a particular style" (1933).

"Something that has been set" (1510s), hence the use in tennis (1570s) and the theatrical meaning "scenery for an individual scene in a play, etc.," recorded from 1859. Other meanings OED groups under "miscellaneous technical senses" include "piece of electrical apparatus" (1891, first in telegraphy); "burrow of a badger" (1898). Old English had set "seat," in plural "camp; stable," but OED finds it "doubtful whether this survived beyond OE." Compare set (n.1).

Set (n.1) and set (n.2) are not always distinguished in dictionaries; OED has them as two entries, Century Dictionary as one. The difference of opinion seems to be whether the set meaning "group, grouping" (here (n.2)) is a borrowing of the unrelated French word that sounds like the native English one, or a borrowing of the sense only, which was absorbed into the English word.
Set Look up Set at Dictionary.com
Egyptian god, from Greek Seth, from Egyptian Setesh.
set off (v.) Look up set off at Dictionary.com
verbal phrase; see set (v.) + off (adv.). From 1590s as "make prominent by contrast," 1610s as "adorn." Intransitive sense of "start on a journey" is from 1774. Meaning "separate from contect" (in typography) is from 1824; sense of "ignite, discharge, cause to explode" is from 1810.
set-aside (n.) Look up set-aside at Dictionary.com
1943, from verbal phrase (early 15c.); see set (v.) + aside (adv.).
set-to (n.) Look up set-to at Dictionary.com
"bout, fight," 1743, originally pugilistic slang, from verbal phrase; see set (v.) + to.
set-up (n.) Look up set-up at Dictionary.com
"arrangement," 1890, from verbal phrase set up, attested from c.1200 as "to make ready for use" and from 1950 (in pugilism) as "to bring (someone) to a vulnerable position;" from set (v.) + up (adv.). The verbal phrase also can mean "to establish" (early 15c.) and "put drinks before customers" (1880).
seta (n.) Look up seta at Dictionary.com
plural setae, 1793, from Latin seta "bristle," from PIE root *sai- "to tie, bind" (see sinew). Related: Setaceous.
setback (n.) Look up setback at Dictionary.com
also set-back, 1670s, "reversal, check to progress," from set (v.) + back (adv.). Sometimes backset was used in the same sense. Meaning "space between a building and a property line" is from 1916. To set (someone) back "cost" is from 1900.
Seth Look up Seth at Dictionary.com
masc. proper name, Biblical third son of Adam, literally "set, appointed," from Hebrew Sheth, from shith "to put, set." The Gnostic sect of Sethites (2c.) believed Christ was a reappearance of Seth, whom they venerated as the first spiritual man.
setness (n.) Look up setness at Dictionary.com
1640s, from set (n.2) + -ness. Old English had setnes, which was pressed into service to translate various ideas in Roman law and Christianity: "foundation, creation, construction; size, extent; law, ordinance; instruction; sentence."
sett (n.) Look up sett at Dictionary.com
see set (n.1).
The extra t is an arbitrary addition in various technical senses, from a lawn-tennis to a granite set. Each class of persons has doubtless added it to distinguish the special sense that means most to it from all others ; but so many are the special senses that the distinction is now no more distinctive than an Esq. after a man's name, & all would do well to discard it. [Fowler]
settee (n.) Look up settee at Dictionary.com
"long seat with back and arms," 1716, perhaps a variant of settle (n.), or a diminutive of set (v.) "act of setting."