Security \Se*cu"ri*ty\, n.; pl. Securities. [L. securitas: cf. F. s['e]curit['e]. See Secure, and cf. Surety.]

1. The condition or quality of being secure; secureness. Specifically:
   (a) Freedom from apprehension, anxiety, or care; confidence of power of safety; hence, assurance; certainty.

His trembling hand had lost the ease, Which marks security to please. --Sir W. Scott.
   (b) Hence, carelessness; negligence; heedlessness.

He means, my lord, that we are too remiss, Whilst Bolingbroke, through our security, Grows strong and great in substance and in power. --Shak.
   (c) Freedom from risk; safety.

Give up yourself merely to chance and hazard, From firm security. --Shak.

Some . . . alleged that we should have no security for our trade. --Swift.

2. That which secures or makes safe; protection; guard; defense. Specifically:
   (a) Something given, deposited, or pledged, to make certain the fulfillment of an obligation, the performance of a contract, the payment of a debt, or the like; surety; pledge.

Those who lent him money lent it on no security but his bare word. --Macaulay.
   (b) One who becomes surety for another, or engages himself for the performance of another's obligation.

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

Syn: Protection; defense; guard; shelter; safety; certainty; ease; assurance; carelessness; confidence; surety; pledge; bail.

Source: Webster's Revised Unabridged Dictionary (1913)