security

security — noun

1. ways of keeping people, buildings, or countries safe from crime, attacks, or oth

1.nounB1
Definition

ways of keeping people, buildings, or countries safe from crime, attacks, or other threats.

Example

The airport tightened security after a suspicious bag was left near the check-in desks.

tightened security — increased protective measures after an incident

Our apartment building has round-the-clock security with cameras in the lobby and hallways.

round-the-clock security — continuous protection

Common collocations
  • tighten security
  • improve security
  • national security
  • home security
  • airport security
  • security measures
  • security system
Synonyms
  • safety

    focuses on the state of being free from harm; security emphasises the measures taken to achieve that state

  • protection

    broader term covering any act of keeping someone safe; security often implies organised systems

  • defence

    implies active resistance against a threat, whereas security is more about prevention

Antonyms
  • danger

    the state of being exposed to harm or risk

  • threat

    an indication of something harmful about to happen

Grammar Patterns

security + against/threats

national/personal/home/airport security

Usage Note

Commonly appears in compound nouns such as security guard, security camera, security system, and security check. Uncountable — do not use with an indefinite article.

Common Mistakes

I work in security guard.
I work as a security guard.
'Security guard' is a job title; use 'as a' after a verb like 'work.'

2. the people whose job is to guard a building, event, or area and make sure nobody

2.nounB1
Definition

the people whose job is to guard a building, event, or area and make sure nobody enters without permission.

Example

The security guards at the front desk asked Christopher to show his ID card.

security guard — common compound noun for a person in this role

Felix called building security when he noticed a stranger near the basement door.

Common collocations
  • call security
  • hire security
  • security guard
  • building security
  • event security
  • security personnel
  • security staff
Synonyms
  • guards

    more specific — refers to individual people rather than the team as a whole

  • security personnel

    more formal register, often used in official notices or reports

Grammar Patterns

security + singular verb

building/event/venue security

Usage Note

When referring to the people rather than the concept, this sense behaves as a collective noun and takes a singular verb. Example: 'Security is checking all bags.'

Common Mistakes

The security are checking bags.
The security is checking bags.
When security means 'the staff,' use a singular verb as with other collective nouns.

3. the condition of having a steady income or job that is not at risk, so you can p

3.nounB2
Definition

the condition of having a steady income or job that is not at risk, so you can plan for the future without worry.

Example

After ten years with the same company, Soraya finally felt some job security.

collocation: job security

Many people choose jobs in public service because they offer greater financial security.

collocation: financial security

Common collocations
  • job security
  • financial security
  • economic security
  • sense of security
  • security of employment
  • long-term security
Synonyms
  • stability

    focuses on the state of being steady and not changing; security adds a sense of protection against loss

  • certainty

    emphasises the absence of doubt; security is more about freedom from worry about the future

Antonyms
  • insecurity

    the state of not being sure about keeping your job or income

  • instability

    a situation that is likely to change or fail

Grammar Patterns

job/employment/financial security

sense of security

security of + noun phrase

Usage Note

Commonly occurs in the fixed phrases 'job security' and 'financial security.' Uncountable — do not precede with 'a' or 'an.'

Common Mistakes

I have a job security at my current company.
I have job security at my current company.
'Job security' is uncountable and does not take an article.

4. property that a borrower leaves with a lender until a debt is fully paid, and wh

4.nounB2
Definition

property that a borrower leaves with a lender until a debt is fully paid, and which the lender may keep if the borrower fails to pay.

Example

The bank asked Nikhil to use his house as security for the business loan.

pattern: use [asset] as security for [loan]

If you cannot repay the loan, the lender can take the security you offered.

Common collocations
  • as security
  • provide security
  • offer security
  • use as security for
  • security for a loan
  • additional security
Synonyms
  • collateral

    the standard technical term in banking for property pledged against a loan

  • guarantee

    broader term that can also refer to a promise rather than physical property

Grammar Patterns

use [asset] as security for [loan]

provide/offer security

as security

Usage Note

Common in legal and banking contexts. The phrase 'as security for [a loan]' is a standard construction. The borrower is the one who 'provides' or 'offers' security.

Common Mistakes

The bank asked for my house as a security.
The bank asked for my house as security.
In this sense, 'security' is uncountable; do not use 'a.'

5. tradable financial assets, such as shares in companies or bonds issued by govern

5.nounC1
Definition

tradable financial assets, such as shares in companies or bonds issued by governments, that investors buy to earn income.

Example

The investment firm advised clients to put their money into government securities.

common collocation: government securities

Apinya bought a mix of securities, including company shares and government bonds.

Common collocations
  • government securities
  • corporate securities
  • trade securities
  • securities market
  • securities trading
  • mortgage-backed securities
  • debt securities
  • equity securities
Synonyms
  • stocks

    refers specifically to shares in companies, not bonds or other instruments

  • bonds

    a specific type of security that represents debt rather than ownership

  • financial instruments

    a broader formal term that includes derivatives and other complex products

Grammar Patterns

government/corporate securities

trade in securities

securities market

Usage Note

In financial contexts, this sense almost always appears in the plural form 'securities.' Common types include government securities, corporate securities, and mortgage-backed securities.

Common Mistakes

I bought some security from the stock market.
I bought some securities from the stock market.
When referring to stocks and bonds, use the plural form 'securities.'

6. knowing that you are safe, accepted, and cared for by your family or the people

6.nounB2
Definition

knowing that you are safe, accepted, and cared for by your family or the people close to you.

Example

Children need emotional security to grow up feeling confident and happy.

A loving home gives most people a sense of security they carry through life.

phrase: a sense of security

Common collocations
  • emotional security
  • sense of security
  • feel a sense of security
  • security in a relationship
  • provide security for a child
  • lack of security
Synonyms
  • reassurance

    the act of being made to feel less worried; security is a more stable, ongoing state

  • comfort

    a broader term for physical or emotional ease; security adds a sense of safety from harm

Antonyms
  • insecurity

    the feeling of not being good enough or not being loved or accepted

  • anxiety

    a feeling of worry or unease, often about relationships or acceptance

Grammar Patterns

emotional security

sense of security

security in [relationship/family]

Usage Note

Often occurs in the phrase 'sense of security' in psychological or relational contexts. Distinguished from sense 3 (financial) by its focus on relationships and emotional well-being rather than money or employment.

Common Mistakes

I need more security with my boyfriend.' (vague)
I need more emotional security in my relationship.
Be specific about the type of security to avoid confusion with financial or physical meanings.

Word family

  • secure
    adjectiveB2
  • secure
    verbB2
  • securely
    adverbC1
  • insecurity
    nounB2
  • insecure
    adjectiveB2
  • security guard
    nounB1
  • securitize
    verbC2
  • securitization
    nounC2

Synonym discussion

Sense: noun/1

All four words relate to keeping people or things free from harm, but they differ in scope and focus. Safety describes a state — being free from danger or injury. Security goes further, implying active measures (locks, guards, systems) that create and maintain that state. Protection is the broadest term, covering any action or thing that shields someone from harm, whether through laws, equipment, or physical barriers. Defence specifically implies resistance against a known or expected attack, often in military or sporting contexts. A safeguard is a specific rule, device, or procedure designed to prevent a particular problem. For example, a seatbelt is a safety feature, a home alarm system provides security, a vaccine offers protection against disease, and a password is a safeguard against data theft.

safety ↗protection ↗defence ↗safeguard ↗

Common collocations

Nouns

Adverbs

Phrases

  • sense of security
  • security measures
  • security breach
  • security detail
  • security clearance
  • social security
  • security deposit

Prepositions

Etymology

LatinFrenchEnglish

Security comes from the Latin word securus, which means 'free from care' — formed from se- ('without') and cura ('care' or 'worry'). It entered English through Old French securite. The original meaning was simply 'freedom from danger,' and over time it expanded to cover financial guarantees, job stability, and emotional well-being.