Definition of security
2a : something given, deposited, or pledged to make certain the fulfillment of an obligationb : surety
3 : an instrument of investment in the form of a document (such as a stock certificate or bond) providing evidence of its ownership
Examples of security in a sentence
We must insure our national security.
The college failed to provide adequate security on campus after dark.
There was a lapse in security and the inmates escaped.
We have to go through security at the airport.
We called security when we found the door open.
The meeting was held under tight security.
The prisoner was being kept under maximum security.
I like the security of knowing there will be someone there to help me when I need help.
Growing up in a close family gave her a sense of security.
First Known Use of security
SECURITY Defined for English Language Learners
Definition of security for English Language Learners
: the state of being protected or safe from harm
: things done to make people or places safe
: the area in a place (such as an airport) where people are checked to make sure they are not carrying weapons or other illegal materials
SECURITY Defined for Kids
Definition of security for Students
1 : the state of being safe : safety national security
2 : freedom from worry or anxiety financial security
3 : something given as a pledge of payment He gave security for a loan.
4 : something (as a stock certificate) that is evidence of debt or ownership
Medical Definition of security
: freedom from fear or anxiety need for security dates back into infancy—K. C. Garrison
Legal Definition of security
2 : evidence of indebtedness, ownership, or the right to ownership; specifically : evidence of investment in a common enterprise (as a corporation or partnership) made with the expectation of deriving a profit solely from the efforts of others who acquire control over the funds invested a security involves some form of investment contract — see also due diligence asset–backed security : a security (as a bond) that represents ownership in or is secured by a pool of assets (as loans or receivables) that have been securitized bearer security : a security (as a bearer bond) that is not registered and is payable to anyone in possession of it certificated security \sər-ˈti-fə-ˌkā-təd-\ : a security that belongs to or is divisible into a class or series of shares, participations, interests, or obligations, is a commonly recognized medium of investment, and is represented on an instrument payable to the bearer or a specified person or on an instrument registered on books by or on behalf of the issuer convertible security : a security (as a share of preferred stock) that the owner has the right to convert into a share or obligation of another class or series (as common stock) debt security : a security (as a bond) serving as evidence of the indebtedness of the issuer (as a government or corporation) to the owner equity security : a security (as a share of stock) serving as evidence of an ownership interest in the issuer; also : one convertible to or serving as evidence of a right to purchase, sell, or subscribe to such a security exempted security : a security (as a government bond) exempt from particular requirements of the Securities and Exchange Commission (as those relating to registration on a security exchange) fixed–income security : a security (as a bond) that provides a fixed rate of return on an investment (as because of a fixed interest rate or dividend) government security : a security (as a Treasury bill) that is issued by a government, a government agency, or a corporation in which a government has a direct or indirect interest hybrid security : a security with characteristics of both an equity security and a debt security mortgage–backed security : a security that represents ownership in or is secured by a pool of mortgage obligations; specifically : a pass-through security based on mortgage obligations pass–through security : a security representing an ownership interest in a pool of debt obligations from which payments of interest and principal pass from the debtor through an intermediary (as a bank) to the investor; especially : one based on a pool of mortgage obligations guaranteed by a federal government agency — compare collateralized mortgage obligation, remic registered security 1 : a security (as a registered bond) whose owner is registered on the books of the issuer 2 : a security that is to be offered for sale and for which a registration statement has been submitted restricted security : a security accompanied by restrictions on its free transfer or registration of transfer shelf security : a corporate security held for deferred issue in a shelf registration Treasury security : a security issued by a government treasury : treasury 3 uncertificated security \ˌən-sər-ˈti-fə-ˌkā-təd-\ : a security that belongs to or is divisible into a class or series of shares, participations, interests, or obligations, that is a commonly recognized medium of investment, that is not represented by an instrument, and the transfer of which is registered on books by or on behalf of the issuer unregistered security : a security for which a registration statement has not been filed when–issued security : a security traded on a conditional basis prior to its issue
3a : measures taken to guard against espionage or sabotage, crime, attack, or escape b : an organization or department whose task is security
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