secure (v.) Look up secure at Dictionary.com
c. 1600, "to make safe," from secure (adj.). Meaning "ensure, make certain" is from 1650s; that of "seize and hold" is from 1640s; sense of "get possession" is from 1743. Related: Secured; securing.
security (n.) Look up security at Dictionary.com
mid-15c., "condition of being secure," from Latin securitas, from securus "free from care" (see secure). Replacing sikerte (early 15c.), from an earlier borrowing from Latin; earlier in the sense "security" was sikerhede (early 13c.); sikernesse (c. 1200).

Meaning "something which secures" is from 1580s; "safety of a state, person, etc." is from 1941. Legal sense of "property in bonds" is from mid-15c.; that of "document held by a creditor" is from 1680s. Phrase security blanket in figurative sense is attested from 1966, in reference to the crib blanket carried by the character Linus in the "Peanuts" comic strip (1956).
sedan (n.) Look up sedan at Dictionary.com
1630s, "covered chair on poles," possibly from a southern Italian dialect derivative of Italian sede "chair" (compare Italian seggietta, 1590s; the thing itself was said to have been introduced from Naples), from Latin sedes, related to sedere "sit" (see sedentary). Since Johnson's conjecture, often derived from the town of Sedan in France, where it was said to have been made or first used, but historical evidence for this is lacking.

Introduced in England by Sir Sanders Duncombe in 1634 and first called a covered chair. "In Paris the sedan-chair man was usually an Auvergnat, in London an Irishman" ["Encyclopaedia Britannica," 1929]. Meaning "closed automobile seating four or more" first recorded 1912, American English.
sedate (adj.) Look up sedate at Dictionary.com
"calm, quiet," 1660s, from Latin sedatus "composed, moderate, quiet, tranquil," past participle of sedare "to settle, calm," causative of sedere "to sit" (see sedentary). Related: Sedately.
sedate (v.) Look up sedate at Dictionary.com
"treat with sedatives," 1945, a back-formation from the noun derivative of sedative (adj.). The word also existed 17c. in a sense "make calm or quiet." Related: Sedated; sedating.
sedation (n.) Look up sedation at Dictionary.com
early 15c., "alleviation of pain;" 1540s, "act of making calm," from Middle French sédation and directly from Latin sedationem (nominative sedatio) "a quieting, assuaging, a calming," noun of action from past participle stem of sedare (see sedate (adj.)).
sedative (adj.) Look up sedative at Dictionary.com
"tending to calm or soothe," early 15c., from Medieval Latin sedativus "calming, allaying," from sedat-, past participle stem of sedare, causative of sedere "to sit" (see sedentary). The noun derivative meaning "a sedative drug" is attested from 1785. Hence, "whatever soothes or allays."
sedentary (adj.) Look up sedentary at Dictionary.com
1590s, "remaining in one place," from Middle French sédentaire (16c.) and directly from Latin sedentarius "sitting, remaining in one place," from sedentem (nominative sedens), present participle of sedere "to sit; occupy an official seat, preside; sit still, remain; be fixed or settled," from PIE root *sed- (1) "to sit" (cognates: Sanskrit a-sadat "sat down," sidati "sits;" Old Persian hadis "abode;" Greek ezesthai "to sit," hedra "seat, chair, face of a geometric solid;" Old Irish suide "seat, sitting;" Welsh sedd "seat," eistedd "sitting;" Old Church Slavonic sežda, sedeti "to sit;" Lithuanian sedmi "to sit;" Russian sad "garden," Lithuanian soditi "to plant;" Gothic sitan, Old English sittan "to sit;" see sit). Of persons, the sense "not in the habit of exercise" is recorded from 1660s.
Seder (n.) Look up Seder at Dictionary.com
home service on the first nights of Passover, 1865, from Hebrew sedher "order, procedure," related to sedherah "row, rank."
sederunt (n.) Look up sederunt at Dictionary.com
"sitting, session," Latin, literally "they sat" (typical opening word in recordings of such proceedings), third person plural past tense of sedere "to sit" (see sedentary).
sedge (n.) Look up sedge at Dictionary.com
"coarse grass-like plant growing in wet places," Old English secg "sedge, reed, rush," from Proto-Germanic *sagjoz (cognates: Low German segge, German Segge), probably from PIE root *sek- "to cut" (see section (n.) and compare Old English secg, identical in form but meaning "sword;" and German schwertel-gras "sedge" from schwert "sword"), on notion of plant with "cutting" leaves (compare etymological sense of gladiolus). Old Irish seisg, Welsh hesgreed "rush" might represent a similar sense development from the same root. Often spelled seg, segg until present form triumphed early 1900s.
sediment (n.) Look up sediment at Dictionary.com
1540s, "matter which settles at the bottom of water or other liquid," from Middle French sédiment (16c.) and directly from Latin sedimentum "a settling, sinking down," from stem of sedere "to settle, sit" (see sedentary).
sedimentary (adj.) Look up sedimentary at Dictionary.com
1764, from sediment + -ary. Sedimentary rock attested by 1830 (in Lyell). Sedimental (adj.) is recorded from c. 1600.
sedimentation (n.) Look up sedimentation at Dictionary.com
1845, from sediment + -ation.
sedition (n.) Look up sedition at Dictionary.com
mid-14c., "rebellion, uprising, revolt, concerted attempt to overthrow civil authority; violent strife between factions, civil or religious disorder, riot; rebelliousness against authority," from Old French sedicion (14c., Modern French sédition) and directly from Latin seditionem (nominative seditio) "civil disorder, dissention, strife; rebellion, mutiny," literally "a going apart, separation," from se- "apart" (see secret) + itio "a going," from past participle of ire "to go" (see ion).

Meaning "conduct or language inciting to rebellion against a lawful government" is from 1838. An Old English word for it was folcslite. Less serious than treason, as wanting an overt act, "But it is not essential to the offense of sedition that it threaten the very existence of the state or its authority in its entire extent" [Century Dictionary].
seditious (adj.) Look up seditious at Dictionary.com
mid-15c., from Middle French seditieux, from Latin seditiosus "full of discord, factious, mutinous," from seditio (see sedition). Related: Seditiously; seditiousness.
seduce (v.) Look up seduce at Dictionary.com
1520s, "to persuade a vassal, etc., to desert his allegiance or service," from Latin seducere "lead away, lead astray," from se- "aside, away" (see secret (n.)) + ducere "to lead" (see duke (n.)). Sexual sense, now the prevailing one, is attested from 1550s and apparently was not in Latin. Originally "entice (a woman) to a surrender of chastity." Related: Seduced; seducing.

Replaced Middle English seduisen (late 15c.), from Middle French séduire "seduce," from Old French suduire "to corrupt, seduce," from Latin subducere "draw away, withdraw, remove" (see subduce).
seductible (adj.) Look up seductible at Dictionary.com
1620s, from seduct-, past participle stem of Latin seducere (see seduce) + -ible. Related: Seductibly; seductibility.
seduction (n.) Look up seduction at Dictionary.com
1520s, from Middle French séduction, from Latin seductionem (nominative seductio), noun of action from past participle stem of seducere (see seduce). Originally with reference to actions or beliefs; sexual sense is from 1769, originally always with women as the objects. Earlier appearance of the word in Middle English with a sense "treason, treachery" probably is a confusion with sedition, which confusion also is found in Old French seducion "treason, betrayal."
seductive (adj.) Look up seductive at Dictionary.com
1740, from Latin seduct-, past participle stem of seducere (see seduce) + -ive. Related: Seductively; seductiveness. Middle English had seducious "deceitful, devious" (mid-15c.).
seductress (n.) Look up seductress at Dictionary.com
1803, "female seducer," with -ess + obsolete seductor (late 15c., displaced by seducer), from a direct borrowing of the Latin agent noun of seducere (see seduce).
sedulity (n.) Look up sedulity at Dictionary.com
1540s, from Latin sedulitas "assiduity, application," noun of quality from sedulus (see sedulous).
sedulous (adj.) Look up sedulous at Dictionary.com
1530s, from Latin sedulus "attentive, painstaking, diligent, busy, zealous," probably from sedulo (adv.) "sincerely, diligently," from sedolo "without deception or guile," from se- "without, apart" (see secret) + dolo, ablative of dolus "deception, guile," cognate with Greek dolos "ruse, snare." Related: Sedulously; sedulousness.
sedum (n.) Look up sedum at Dictionary.com
mid-15c., from Latin sedum "houseleek."
see (n.) Look up see at Dictionary.com
c. 1300, "throne of a bishop, archbishop, or pope," also "throne of a monarch, a goddess, Antichrist, etc.," from Old French sie "seat, throne; town, capital; episcopal see," from Latin sedem (nominative sedes) "seat, throne, abode, temple," related to sedere "to sit" (see sedentary). Early 14c. as "administrative center of a bishopric;" c. 1400 as "province under the jurisdiction of a bishop."
see (v.) Look up see at Dictionary.com
Old English seon "to see, look, behold; observe, perceive, understand; experience, visit, inspect" (contracted class V strong verb; past tense seah, past participle sewen), from Proto-Germanic *sekhwan (source also of Old Saxon, Old High German sehan, Middle High German, German sehen, Old Frisian sia, Middle Dutch sien, Old Norse sja, Gothic saihwan), from PIE root *sekw- (2) "to see," which is probably identical with *sekw- (1) "to follow" (see sequel), a root which produced words for "say" in Greek and Latin, and also words for "follow" (such as Latin sequor), but "opinions differ in regard to the semantic starting-point and sequences" [Buck]. Thus see might originally mean "follow with the eyes."

Used in Middle English to mean "behold in the imagination or in a dream" (c. 1200), "to recognize the force of (a demonstration)," also c. 1200. Sense of "escort" (as in to see (someone) home) first recorded 1607 in Shakespeare. Meaning "to receive as a visitor" is attested from c. 1500. Gambling sense of "equal a bet" is from 1590s. See you as a casual farewell first attested 1891. Let me see as a pausing statement is recorded from 1510s.
see-saw (n.) Look up see-saw at Dictionary.com
also seesaw, 1630s, in see-saw-sacke a downe (like a Sawyer), words in a rhythmic jingle used by children and repetitive motion workers, probably imitative of the rhythmic back-and-forth motion of sawyers working a two-man saw over wood or stone (see saw (n.1). Ha ha.). Reference to a game of going up and down on a balanced plank is recorded from 1704; figurative sense is from 1714. Applied from 1824 to the plank arranged for the game.
see-saw (v.) Look up see-saw at Dictionary.com
also seesaw, "move up and down," 1712, from see-saw (n.). Related: See-sawed; see-sawing.
see-through (adj.) Look up see-through at Dictionary.com
1950, from the verbal phrase (c. 1400); see see (v.) + through (adv.).
seed (n.) Look up seed at Dictionary.com
Old English sed, sæd "that which may be sown; an individual grain of seed; offspring, posterity," from Proto-Germanic *sediz "seed" (cognates: Old Norse sað, Old Saxon sad, Old Frisian sed, Middle Dutch saet, Old High German sat, German Saat), from PIE *se-ti- "sowing," from root *se- (1) "to sow" (see sow (v.)). Figurative use in Old English. Meaning "offspring, progeny" rare now except in biblical use. Meaning "semen" is from c. 1300. For sporting sense, see seed (v.).
seed (v.) Look up seed at Dictionary.com
late 14c., "to flower, flourish; produce seed;" mid-15c., "to sow with seed," from seed (n.). Meaning "remove the seeds from" is from 1904. Sporting (originally tennis) sense (1898) is from notion of spreading certain players' names so as to ensure they will not meet early in a tournament. The noun in this sense is attested from 1924. Related: Seeded; seeding.
seed-cake (n.) Look up seed-cake at Dictionary.com
1570s, from seed (n.) + cake (n.).
seeded (adj.) Look up seeded at Dictionary.com
1922 in the sports sense (originally tennis), past participle adjective from seed (v.).
seedling (n.) Look up seedling at Dictionary.com
"young plant developed from seed," 1650s, from seed (n.) + diminutive suffix -ling.
seedy (adj.) Look up seedy at Dictionary.com
mid-15c., "fruitful, abundant," from seed (n.) + -y (2). From 1570s as "abounding in seeds." Meaning "shabby" is from 1739, probably in reference to the appearance of a flowering plant that has run to seed. Related: Seediness.
seeing (adj.) Look up seeing at Dictionary.com
c. 1300, present participle adjective from see (v.). Seeing Eye dog first attested 1929, American English, trademarked by Seeing Eye Inc. of New Jersey.
seek (v.) Look up seek at Dictionary.com
Old English secan "inquire, search for; pursue; long for, wish for, desire; look for, expect from," influenced by Old Norse soekja, both from Proto-Germanic *sokjan (cognates: Old Saxon sokian, Old Frisian seka, Middle Dutch soekan, Old High German suohhan, German suchen, Gothic sokjan), from PIE *sag-yo-, from root *sag- "to track down, seek out" (cognates: Latin sagire "to perceive quickly or keenly," sagus "presaging, predicting," Old Irish saigim "seek"). The natural modern form of the Anglo-Saxon word as uninfluenced by Norse is in beseech. Related: Sought; seeking.
seeker (n.) Look up seeker at Dictionary.com
early 14c., agent noun from seek. The religious sect of the Seekers is attested from 1645.
seem (v.) Look up seem at Dictionary.com
c. 1200, "to appear to be;" c. 1300, "to be fitting, be appropriate, be suitable," though the more recent sense in English is the etymological one; from Old Norse soema "to honor; to put up with; to conform to (the world, etc.)," verb derived from adjective soemr "fitting," from Proto-Germanic *somi- (cognates: Old English som "agreement, reconciliation," seman "to conciliate," source of Middle English semen "to settle a dispute," literally "to make one;" Old Danish some "to be proper or seemly"), from PIE *som-i-, from root *sem- "one, as one" (see same). Related: Seemed; seeming.
seeming (adj.) Look up seeming at Dictionary.com
late 14c., present participle adjective from seem. Seemingly in sense of "to all appearances" recorded from 1590s.
seemly (adj.) Look up seemly at Dictionary.com
"of pleasing or good appearance," also "proper, tasteful, decorous," early 13c., semlich, from Old Norse soemiligr "becoming, honorable," from soemr (see seem). Related: Seemliness. Old Norse also had soemleitr "fine to look at."
seen Look up seen at Dictionary.com
Middle English sein, from Old English gesegen, gesewen, past participle of seon (see see (n.)). From c. 1200 as "perceived, discovered." To have seen everything as a hyperbolic expression of astonishment is from 1941.
When you have seen one of their Pictures, you have seen all. [Blake, c. 1811]
seep (v.) Look up seep at Dictionary.com
1790, variant of sipe (c. 1500), possibly from Old English sipian "to seep," from Proto-Germanic *sip- (cognates: Middle High German sifen, Dutch sijpelen "to ooze"), from PIE root *seib- "to pour out, drip, trickle" (see soap (n.)). Related: Seeped; seeping.
seepage (n.) Look up seepage at Dictionary.com
1825, from seep + -age.
seer (n.) Look up seer at Dictionary.com
late 14c., "one to whom divine revelations are made," agent noun from see (v.). Originally rendering Latin videns, Greek bleptor (from Hebrew roeh) in Bible translations (such as I Kings ix:9). Literal sense of "one who sees" is attested from early 15c.
seersucker (n.) Look up seersucker at Dictionary.com
1722, from Hindi sirsakar, East Indian corruption of Persian shir o shakkar "striped cloth," literally "milk and sugar," a reference to the alternately smooth and puckered surfaces of the stripes. From Persian shir (cognate with Sanskrit ksiram "milk") + shakar (cognate with Pali sakkhara, Sanskrit sarkara "gravel, grit, sugar;" see sugar (n.)).
seethe (v.) Look up seethe at Dictionary.com
Old English seoþan "to boil," also figuratively, "be troubled in mind, brood" (class II strong verb; past tense seaþ, past participle soden), from Proto-Germanic *seuthan (cognates: Old Norse sjoða, Old Frisian siatha, Dutch zieden, Old High German siodan, German sieden "to seethe"), from PIE root *seut- "to seethe, boil."

Driven out of its literal meaning by boil (v.); it survives largely in metaphoric extensions. Figurative use, of persons or populations, "to be in a state of inward agitation" is recorded from 1580s (implied in seething). It had wider figurative uses in Old English, such as "to try by fire, to afflict with cares." Now conjugated as a weak verb, and past participle sodden (q.v.) is no longer felt as connected.
seether (n.) Look up seether at Dictionary.com
late 14c., "one employed in boiling," agent noun from seethe.
segment (n.) Look up segment at Dictionary.com
1560s, from Latin segmentum "a strip or piece cut off, a cutting, strips of colored cloth," from secare "to cut" (see section (n.)), with euphonious alteration of -c- to -g- before -m-. Latin segmentum was used in Medieval Latin as a geometry term, translating Greek tmema, and the word was first picked up in English in this sense. Meaning "segmental portion of anything circular" is from 1640s; general sense of "a division, section" is from 1762.
segment (v.) Look up segment at Dictionary.com
1859, intransitive, in reference to cell division, from segment (n.). Transitive sense, "divide (something) into segments" is from 1872. Related: Segmented; segmenting.