se·cu·ri·ty | \ si-ˈkyu̇r-ə-tē , -ˈkyər- \
plural securities

Definition of security 

1 : the quality or state of being secure: such as

a : freedom from danger : safety

b : freedom from fear or anxiety

c : freedom from the prospect of being laid off job security

2a : something given, deposited, or pledged to make certain the fulfillment of an obligation

b : surety

3 : an instrument of investment in the form of a document (such as a stock certificate or bond) providing evidence of its ownership

4a : something that secures : protection

b(1) : measures taken to guard against espionage or sabotage, crime, attack, or escape

(2) : an organization or department whose task is security

Keep scrolling for more

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.
See More

Recent Examples on the Web

Before his sentencing, Saucier and his attorney made a similar argument that was eventually disregarded by a judge who sentenced him for what was perceived as a lack of judgment rather than an attempt to thwart national security. Nicholas Rondinone,, "In Lawsuit Citing Clinton Email Probe, Groton Sailor Pardoned By Trump Seeks $20M In Damages," 13 July 2018 During the fight, the rapper reportedly punched member of the club’s security in the face and caused the police to get involved. Jay R. Jordan, Houston Chronicle, "Rapper Tekashi 6ix9ine arrested in New York for alleged assault inside Houston’s Galleria Mall," 12 July 2018 Trump imposed the trade barriers in the name of national security, infuriating foreign leaders and prompting bipartisan outrage in Congress. Michael Collins, USA TODAY, "Senators blast Trump's 'reckless' tariffs, warn of impact on farmers, businesses," 12 July 2018 There’s already plenty to cut without compromising national security. Lindsay Koshgarian, Fortune, "Trump’s Complaints About NATO Defense Spending Don’t Add Up," 12 July 2018 Your company hadn’t been particularly plagued by that, but many others in this space have, this idea of security in general. Recode Staff, Recode, "Full transcript: Box CEO Aaron Levie on Recode Decode," 11 July 2018 On Monday the Senate passed a nonbinding resolution designed to give Congress more influence over trade penalties imposed in the name of national security. CBS News, "Paul Ryan criticizes Trump's China tariffs, saying they aren't "the right way to go"," 11 July 2018 In a sign of bipartisan trade frustration, the Senate voted 88-11 Wednesday for a nonbinding resolution that calls on the White House to seek congressional approval before issuing tariffs in the interest of national security. Jim Puzzanghera,, "After Trump's new tariff threat, China may either have to blink or widen the trade war," 11 July 2018 Last week, Trump’s national security advisers, who have traditional Republican views toward NATO (good) and Russia (bad), and the allies both expressed their hope that Trump would use the NATO summit to declare victory. Jonathan Chait, Daily Intelligencer, "Trump Is Training His Base to Hate NATO and Like Putin," 10 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'security.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of security

15th century, in the meaning defined at sense 1

Keep scrolling for more

Learn More about security

Statistics for security

Last Updated

18 Sep 2018

Look-up Popularity

Time Traveler for security

The first known use of security was in the 15th century

See more words from the same century

Keep scrolling for more

More Definitions for security

fixed-income security


Financial Definition of fixed-income security

What It Is

A fixed income security is an investment that pays regular income in the form of a coupon payment, interest payment or preferred dividend.

How It Works

Fixed income securities provide periodic income payments at an interest or dividend rate known in advance by the holder. The most common fixed-income securities include Treasury bonds, corporate bonds, certificates of deposit (CDs) and preferred stock.

Holders of Treasury bonds and CDs receive a fixed interest rate based on a par value over a specific period of time. Holders of preferred stock are entitled to a periodic fixed dividend specified by the issuing company for as long as they own the shares.

To illustrate, suppose an investor owns a Treasury bond with a par value of $1,000 and an annual yield of 6%. This investor is guaranteed a payment of $60 each year for the life of the bond. Similarly, an investor who holds preferred stock in Company XYZ might be promised a quarterly dividend payment of $5 per share, which he can dependably receive for as long as he holds the shares.

Why It Matters

Fixed income securities are an excellent choice for risk-averse investors seeking a stable source of income payments at predictable intervals. Fixed income investors and prospective investors should understand that the relatively low risk of fixed income securities generally translates into relatively lower returns.

Source: Investing Answers

hybrid security


Financial Definition of hybrid security

What It Is

A hybrid security is a security that has characteristics of one or more asset classes.

How It Works

For example, a convertible bond is a hybrid security because it is a bond that allows the holder to exchange the bond for other securities (usually the issuer's stock). Mechanically, convertible bonds let the holder use the par value of the bond to purchase other securities from the issuer at a specified price.

For example, consider a Company XYZ bond with a $1,000 par value that is convertible into Company XYZ common stock. If the conversion price of the common shares is $25, then the bondholder can convert each of his or her bonds into 40 Company XYZ shares ($1,000 / $25 = 40). In this scenario, we would say that the conversion ratio is 40:1. Many hybrid securities are callable, meaning that under certain circumstances the issuer can redeem them before they mature.

Why It Matters

Hybrid securities require their investors to conduct extra analyses. For instance, the conversion price is not the only aspect of a convertible bond to analyze. Like other bonds, convertible bonds usually offer a coupon, and their prices are based on prevailing market rates and the credit quality of the issuer. Because conversion would mean losing those interest payments, investors also compare the coupon payment of the bond to the dividend yield of the common shares when they're thinking of converting.

Another thing to consider when investing in hybrid securities is their trading behavior. For instance, the more a convertible bond is "in the money," that is, the more the market value of the shares exceeds the conversion price, the more the bond itself trades like a stock. The bond's price tends to rise as the stock price approaches the conversion price (similar to a call option). The more volatile the stock price when in this zone, the more volatile the bond price. Interestingly, this relationship allows convertible bondholders to participate in the company's stock price appreciation.

Source: Investing Answers



English Language Learners Definition of security

: 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


se·cu·ri·ty | \ si-ˈkyu̇r-ə-tē \
plural securities

Kids Definition of security

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

Keep scrolling for more


se·cu·ri·ty | \ si-ˈkyu̇r-ət-ē \
plural securities

Medical Definition of security 

: freedom from fear or anxiety need for security dates back into infancy —K. C. Garrison


se·cur·i·ty | \ si-ˈkyu̇r-ə-tē \
plural securities

Legal Definition of security 

1a : something (as a mortgage or collateral) that is provided to make certain the fulfillment of an obligation used his property as security for a loan

b : surety — see also security for costs

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 sense 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

Keep scrolling for more

Comments on security

What made you want to look up security? Please tell us where you read or heard it (including the quote, if possible).


by word of mouth

Get Word of the Day daily email!

Test Your Vocabulary

Name that Food Quiz

Spell It

Can you spell these 10 commonly misspelled words?

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!