1.  security(n = noun.state) - the state of being free from danger or injury; "we support the armed services in the name of national security"
is a kind of safety
has particulars: peace, public security, secureness, protection, shelter
Antonym: insecurity
Derived form adjective secure₂

2.  security(n = noun.possession) protection - defense against financial failure; financial independence; "his pension gave him security in his old age"; "insurance provided protection against loss of wages due to illness"
is a kind of assets
has particulars: easy street, hedge, hedging, insurance
Derived form adjective secure₅

3.  security(n = noun.feeling) - freedom from anxiety or fear; "the watch dog gave her a feeling of security"
is a kind of bravery, fearlessness
has particulars: confidence
Derived form adjective secure₁

4.  security(n = noun.possession) certificate - a formal declaration that documents a fact of relevance to finance and investment; the holder has a right to receive interest or dividends; "he held several valuable securities"
is a kind of instrument, legal document, legal instrument, official document
has particulars: agency security, government security, mortgage-backed security, registered security, scrip, stock, stock certificate, tax-exempt, tax-exempt security, bond, bond certificate, zero-coupon security, zero coupon security, partnership certificate, proprietorship certificate, convertible, convertible security, letter security, listed security, otc security, over the counter security, unlisted security

5.  security(n = noun.possession) surety - property that your creditor can claim in case you default on your obligation; "bankers are reluctant to lend without good security"
is a kind of transferred possession, transferred property
has particulars: deposit, earnest, recognisance, recognizance, stock-purchase warrant, stock warrant, warrant

6.  security(n = noun.group) security department - a department responsible for the security of the institution's property and workers; "the head of security was a former policeman"
is a kind of department, section

7.  security(n = noun.communication) surety - a guarantee that an obligation will be met;
is a kind of guarantee, warrant, warrantee, warranty

8.  security(n = noun.artifact) security measure, security system - an electrical device that sets off an alarm when someone tries to break in;
is a kind of electrical device

9.  security(n = noun.act) security measures - measures taken as a precaution against theft or espionage or sabotage etc.; "military security has been stepped up since the recent uprising"
is a kind of guard, precaution, safeguard

1.  The condition or quality of being secure; secureness. [1913 Webster]
"His trembling hand had lost the ease,
Which marks security to please." [1913 Webster]
"He means, my lord, that we are too remiss,
Whilst Bolingbroke, through our security,
Grows strong and great in substance and in power." [1913 Webster]
"Give up yourself merely to chance and hazard,
From firm security." [1913 Webster]
"Some . . . alleged that we should have no security for our trade." [1913 Webster]

2.  That which secures or makes safe; protection; guard; defense. [1913 Webster]
"Those who lent him money lent it on no security but his bare word." [1913 Webster]

3.  An evidence of debt or of property, as a bond, a certificate of stock, etc.; as, government securities. [1913 Webster]

security, n. (pl. -ies)
1 a secure condition or feeling.
2 a thing that guards or guarantees.
3 a the safety of a State, company, etc., against espionage, theft, or other danger. b an organization for ensuring this.
4 a thing deposited or pledged as a guarantee of the fulfilment of an undertaking or the payment of a loan, to be forfeited in case of default.
5 (often in pl.) a certificate attesting credit or the ownership of stock, bonds, etc.

Idiom:
on security of using as a guarantee. security blanket 1 an official sanction on information in the interest of security.
2 a blanket or other familiar object given as a comfort to a child. Security Council a permanent body of the United Nations seeking to maintain peace and security. security guard a person employed to protect the security of buildings, vehicles, etc. security risk a person whose presence may threaten security.

Etymology:
ME f. OF securit{eacute} or L securitas (as SECURE)

N  safety, security, surety, impregnability, invulnerability, invulnerableness, danger past, danger over, storm blown over, coast clear, escape, means of escape, blow valve, safety valve, release valve, sniffing valve, safeguard, palladium, guardianship, wardship, wardenship, tutelage, custody, safekeeping, preservation, protection, auspices, safe-conduct, escort, convoy, guard, shield, guardian angel, tutelary god, tutelary deity, tutelary saint, genius loci, protector, guardian, warden, warder, preserver, custodian, duenna, chaperon, third person, watchdog, bandog, Cerberus, watchman, patrolman, policeman, cop, dick, fuzz, smokey, peeler, zarp, sentinel, sentry, scout, garrison, guardship, refuge &c, anchor, precaution, quarantine, cordon sanitaire, confidence, protect, take care of, preserve, cover, screen, shelter, shroud, flank, ward, guard, secure, entrench, intrench, fence round, house, nestle, ensconce, take charge of, escort, convoy, garrison, watch, mount guard, patrol, make assurance doubly sure, take up a loose thread, take precautions, double reef topsails, seek safety, take shelter, find shelter, Adj, safe, secure, sure, in safety, in security, on the safe side, under the shield of, under the shade of, under the wing of, under the shadow of one's wing, under cover, under lock and key, out of danger, out of the woods, out of the meshes, out of harm's way, unharmed, unscathed, on sure ground, at anchor, high and dry, above water, unthreatened, unmolested, protected, cavendo tutus, panoplied, snug, seaworthy, weatherproof, waterproof, fireproof, defensible, tenable, proof against, invulnerable, unassailable, unattackable, impenetrable, impregnable, imperdible, inexpugnable, Achillean, safe and sound, scathless, unhazarded, not dangerous, unthreatening, harmless, friendly (cooperative), protecting, protective, guardian, tutelary, preservative, trustworthy, ex abundanti cautela, with impunity, all's well, salva res est, suave mari magno, a couvert, e terra alterius spectare laborem, Dieu vous garde.

N  security, guaranty, guarantee, gage, warranty, bond, tie, pledge, plight, mortgage, collateral, debenture, hypothecation, bill of sale, lien, pawn, pignoration, real security, vadium, stake, deposit, earnest, handsel, caution, promissory note, bill, bill of exchange, I, O, U, personal security, covenant, specialty, parole, acceptance, indorsement, signature, execution, stamp, seal, sponsor, cosponsor, sponsion, sponsorship, surety, bail, mainpernor, hostage, godchild, godfather, godmother, recognizance, deed of indemnity, covenant of indemnity, authentication, verification, warrant, certificate, voucher, docket, doquet, record, probate, attested copy, receipt, acquittance, quittance, discharge, release, muniment, title deed, instrument, deed, deed poll, assurance, indenture, charter, charter poll, paper, parchment, settlement, will, testament, last will and testament, codicil, bonis avibus, gone where the woodbine twineth.

N  hope, hopes, desire, fervent hope, sanguine expectation, trust, confidence, reliance, faith, affiance, assurance, secureness, security, reassurance, good omen, good auspices, promise, well grounded hopes, good prospect, bright prospect, clear sky, assumption, presumption, anticipation, hopefulness, buoyancy, optimism, enthusiasm, heart of grace, aspiration, optimist, utopian, utopist, castles in the air, castles in Spain, chateaux en Espagne, le pot aut lait, Utopia, millennium, day dream, golden dream, dream of Alnaschar, airy hopes, fool's paradise, mirage, fond hope, beam of hope, ray of hope, gleam of hope, glimmer of hope, flash of hope, dawn of hope, star of hope, cheer, bit of blue sky, silver lining, silver lining of the cloud, bottom of Pandora's box, balm in Gilead, light at the end of the tunnel, anchor, sheet anchor, mainstay, staff, heaven, hoping, in hopes, hopeful, confident, secure, sanguine, in good heart, buoyed up, buoyant, elated, flushed, exultant, enthusiastic, heartsome, utopian, unsuspecting, unsuspicious, fearless, free from fear, free from suspicion, free from distrust, free from despair, exempt from fear, exempt from suspicion, exempt from distrust, exempt from despair, undespairing, self reliant, probable, on the high road to, within sight of shore, within sight of land, promising, propitious, of promise, full of promise, of good omen, auspicious, de bon augure, reassuring, encouraging, cheering, inspiriting, looking up, bright, roseate, couleur de rose, rose-colored, hopefully, Int, God speed!, nil desperandum, never say die, dum spiro spero, latet scintillula forsan, all is for the best, spero meliora, every cloud has a silver lining, the wish being father to the thought, hope told a flattering tale, rusticus expectat dum defluat amnis, at spes non fracta, ego spem prietio non emo, un Dieu est ma fiance, hope! thou nurse of young desire, in hoc signo spes mea, in hoc signo vinces, la speranza e il pan de miseri, l'esperance est le songe d'un homme eveille, the mighty hopes that make us men, the sickening pang of hope deferred.

agency security, bureau of diplomatic security, canadian security intelligence service, collective security, committee for state security, communications security establishment, convertible security, federal security bureau, federal security service, general security services, government security, homeland security, international relations and security network, letter security, listed security, mortgage-backed security, national security agency, national security council, office of homeland security, otc security, over the counter security, private security force, public security, registered security, security blanket, security consultant, security council, security department, security deposit, security director, security force, security guard, security intelligence, security intelligence review committee, security interest, security measure, security measures, security review, security service, security staff, security system, social security, social security administration, social security number, tax-exempt security, transportation security administration, unlisted security, zero coupon security, zero-coupon security