Online Etymology Dictionary

secularize (v.): 1610s, from secular + -ize. Related: Secularized; secularizing.
secure (adj.): 1530s, "without care," from Latin securus "without care, safe," from *se cura, from se "free from" (see secret) + cura "care" (see cure). Meaning "firmly fixed" (of material things) is from 1841, on notion of "affording grounds for confidence." Related: Securely.
secure (v.): 1590s; see secure (adj.). Related: Secured; securing.
security (n.): mid-15c., "condition of being secure," from Latin securitas, from securus (see secure). Meaning "freedom from care" is from 1550s; that of "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.): 1630s, "covered chair on poles," possibly from a southern Italian dialect derivative of Italian sede "chair" (cf. 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 (v.): "treat with sedatives," 1945, a back-formation from the noun derivative of sedative (adj.). Related: Sedated; sedating.
sedate (adj.): 1660s, from Latin sedatus "composed, moderate, quiet, tranquil," past participle of sedare "to settle, calm," causative of sedere "to sit" (see sedentary).
sedation (n.): 1540s, from Latin sedationem (nominative sedatio), noun of action from past participle stem of sedare (see sedate (adj.)).
sedative (adj.): "tending to calm or soothe," early 15c., from Medieval Latin sedativus "calming, allaying," from past participle stem of sedare (see sedate). The noun derivative meaning "a sedative drug" is attested from 1785.
sedentary (adj.): 1590s, "remaining in one place," from Middle French sedentaire, from Latin sedentarius "sitting, remaining in one place," from sedentem (nominative sedens), present participle of sedere "to sit," from PIE root *sed- "to sit" (cf. 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 sezda, 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, meaning "not in the habit of exercise" is recorded from 1660s.
Seder (n.): home service on the first nights of Passover, 1865, from Hebrew sedher "order, procedure," related to sedherah "row, rank."
sedge (n.): "coarse grass-like plant growing in wet places," Old English secg, from Proto-Germanic *sagjoz (cf. Low German segge, German Segge), from PIE root *sek- "cut" (cf. Old English secg "sword"), on notion of plant with "cutting" leaves (cf. etymological sense of gladiolus, and possible connection to Old Irish seisg, Welsh hesgreed "rush"). Often spelled seg, segg until present form triumphed early 1900s.
sediment (n.): 1540s, from French sédiment (16c.), from Latin sedimentum "a settling, sinking down," from stem of sedere "to settle, sit" (see sedentary).
sedimentary (adj.): 1764, from sediment + -ary. Sedimentary rock attested by 1830 (in Lyell).
sedimentation (n.): 1845, from sediment + -ation.
sedition (n.): late 14c., "rebellion," from Old French sedicion, from Latin seditionem (nominative seditio) "civil disorder, dissention," 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.
seditious (adj.): mid-15c., from Old French seditieux, from Latin seditiosus, from seditionem (see sedition). Related: Seditiously; seditiousness.
seduce (v.): 1520s, "to persuade a vassal, etc., to desert his allegiance or service," from Latin seducere "lead away, lead astray," from se- "aside, away" + ducere "to lead." 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," from sub- "from under, further" + ducere "to lead" (see duke). Sexual sense, now the prevailing one, is attested from 1550s. Related: Seduced; seducing.
seduction (n.): 1520s, from 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.
seductive (adj.): 1760s, from Latin seduct-, past participle stem of seducere (see seduce) + -ive. Related: Seductively; seductiveness.
seductress (n.): 1803; see seduce (Latin stem seduct-) + -ess.
sedulity (n.): 1540s, from Latin sedulitas, noun of quality from sedulus (see sedulous).
sedulous (adj.): 1530s, from Latin sedulus "attentive, painstaking," 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.
sedum (n.): mid-15c., from Latin sedum "houseleek."
see (v.): Old English seon (contracted class V strong verb; past tense seah, past participle sewen), from Proto-Germanic *sekhwanan (cf. 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- "to see," which is "probably" the same base that produced words for "say" in Greek and Latin, and also words for "follow" (cf. Latin sequor), but "opinions differ in regard to the semantic starting-point and sequences" [Buck].

Thus see could 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, "often with ref. to metaphorical light or eyes" [OED], and "to learn by reading" (early 15c.). Past tense saw developed from Old English plural sawon.
When you have seen one of their Pictures, you have seen all. [Blake, c.1811]
Sense of "escort" (e.g. 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. Seeing Eye dog first attested 1929, American English, trademarked by Seeing Eye Inc. of New Jersey.
see (n.): "position of a bishop," c.1300, from Old French sied, sed, from Latin sedem (nominative sedes) "seat, abode," related to sedere "to sit" (see sedentary).
see-through (adj.): 1950, from see (v.) + through (adv.).
seed (v.): "to produce seed," late 14c.; "to sow with seed," mid-15c.; from seed (n.). Sporting (originally tennis) sense (1898) is from notion of spreading certain players' names so as to insure they will not meet early in a tournament. The noun in this sense is attested from 1924. Related: Seeded; seeding.
seed (n.): Old English sed, sæd, from Proto-Germanic *sædis, *sæda- (cf. Old Norse sað, Old Saxon sad, Old Frisian sed, Middle Dutch saet, Old High German sat, German Saat), from root *sæ- "to sow," from PIE root *se- "to sow" (see sow (v.)). Meaning "offspring, progeny" was in Old English, rare now except in biblical use. For sporting sense, see seed (v.).
seedling (n.): "young plant developed from seed," 1660, from seed (n.) + diminutive suffix -ling.
seedy (adj.): mid-15c., "fruitful, abundant," from seed (n.) + -y (2). Meaning "shabby" is from 1739, probably in reference to the appearance of a flowering plant that has run to seed. Related: Seediness.
seek (v.): Old English secan "visit, inquire, pursue," influenced by Old Norse soekja, both from Proto-Germanic *sokjanan (cf. Old Saxon sokian, Old Frisian seka, Middle Dutch soekan, Old High German suohhan, German suchen, Gothic sokjan), from PIE *sag- "to track down, to trace" (cf. Latin sagire "to perceive quickly or keenly," sagus "presaging, predicting," Old Irish saigim "seek"). The modern form of the word as uninfluenced by Old Norse is in beseech. Related: Sought; seeking.
seeker (n.): early 14c., agent noun from seek. The religious sect of the Seekers is attested from 1645.
seem (v.): c.1200, from Old Norse soema "to befit, conform to," and soemr "fitting, seemly," from Proto-Germanic *som- (cf. Old English som "agreement, reconciliation," seman "to conciliate"), related to Proto-Germanic *samon (see same). Related: Seemed; seeming.
seeming (adj.): late 14c., present participle adjective from seem. Seemingly in sense of "to all appearances" recorded from 1590s.
seemly (adj.): "of pleasing or good appearance," early 13c., from Old Norse soemiligr, from soemr (see seem).
seep (v.): 1790, variant of sipe (c.1500), possibly from Old English sipian "to seep," from Proto-Germanic *sip- (cf. Middle High German sifen, Dutch sijpelen "to ooze"). Related: Seeped; seeping.
seepage (n.): 1825, from seep + -age.
seer (n.): late 14c., "one to whom divine revelations are made," from see (v.). Originally rendering Latin videns, Greek bleptor (from Hebrew roeh) in Bible translations (e.g. I Kings ix:9). Literal sense of "one who sees" is attested from early 15c.
seersucker (n.): 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 (cf. Sanskrit ksiram "milk") + shakar (cf. Pali sakkhara, Sanskrit sarkara "gravel, grit, sugar;" see sugar (n.)).
seesaw: also see-saw, 1630s, in see-saw-sacke a downe, 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). 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. The verb is from 1712.
seethe (v.): Old English seoþan "to boil" (class II strong verb; past tense seaþ, past participle soden), from Proto-Germanic *seuthanan (cf. 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, e.g. "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.): late 14c., "one employed in boiling," agent noun from seethe.
segment (n.): 1560s, from Latin segmentum "a strip or piece cut off," originally a geometric term, from secare "to cut" (see section), with euphonious alteration of -c- to -g- before -m-.
segment (v.): 1859, from segment (n.). Related: Segmented; segmenting.
segmentation (n.): 1851, from segment + -ation.
segregate (v.): 1540s, from Latin segregatus, past participle of segregare "separate from the flock, isolate, divide," from *se gregare, from se "apart from" (see secret) + grege, ablative of grex "herd, flock" (see gregarious). Originally often with reference to the religious notion of separating the flock of the godly from sinners. Related: Segregated; segregating.
segregation (n.): 1550s, "act of segregating," from Late Latin segregationem (nominative segregatio), noun of action from segregare (see segregate). Meaning "state of being segregated" is from 1660s. Specific U.S. sense of "enforced separation of races" is attested from 1883.
Rarely are we met with a challenge, not to our growth or abundance, or our welfare or our security, but rather to the values and the purposes and the meaning of our beloved nation. The issue of equal rights for American Negroes is such an issue. And should we defeat every enemy, and should we double our wealth and conquer the stars, and still be unequal to this issue, then we will have failed as a people and as a nation. [Lyndon Johnson, speech introducing Voting Rights Act, March 15, 1965]
segregationist (n.): 1915, from segregation + -ist.
segue (n.): 1740, an instruction in musical scores, from Italian segue, literally "now follows," meaning to play into the following movement without a break, third person singular of seguire "to follow," from Latin sequi "to follow," from PIE *sekw- "to follow" (see sequel). Extended noun sense of "transition without a break" is from 1937; the verb in this sense is first recorded 1958.