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English definition of “security”

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security

noun uk   /sɪˈkjʊə.rɪ.ti/ us    /-ˈkjʊr.ə.t̬i/

security noun (PROTECTION)

B1 [U] protection of a person, building, organization, or country against threats such as crime or attacks by foreign countries: The station was closed for two hours because of a security alert. 30 demonstrators were killed in clashes with the security forces over the weekend. The tighter security measures/precautions include video cameras in the city centre. The students were deported because they posed a threat to national security. The proposed national identity card system would help to tighten security against fraud. The most dangerous criminals are held in maximum-security prisons (= prisons that are as difficult as possible to escape from). [U, + sing/pl verb] the group of people responsible for protecting a building: You'll need to notify security if you want to work late in the office.
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security noun (FIXED)

C1 [U] the fact that something is not likely to fail or be lost: If it's a choice between higher pay and job security, I'd prefer to keep my job. I'm on a temporary contract and have little financial security (= little certainty of having enough money to live on).

security noun (FINANCE)

[U] property or goods that you promise to give to someone if you cannot pay what you owe them: She used her shares in the company as security against a $23 million bank loan. The hotel held onto our baggage as security while we went to the bank to get money to pay the bill.securities [plural] specialized investment in a company or in government debt that can be traded on the financial markets and produces an income for the investor

security noun (CONFIDENCE)

C2 [U] the feeling of being confident in one's family and relationships: Most children need the security of a stable family life.
(Definition of security from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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