[ si-kyoor-i-tee ]
See synonyms for: securitysecurities on

noun,plural se·cu·ri·ties.
  1. freedom from danger, risk, etc.; safety.

  2. freedom from care, anxiety, or doubt; well-founded confidence.

  1. something that secures or makes safe; protection; defense.

  2. freedom from financial cares or from want: The insurance policy gave the family security.

  3. precautions taken to guard against crime, attack, sabotage, espionage, etc.: claims that security was lax at the embassy;the importance of computer security to prevent hackers from gaining access.

  4. a department or organization responsible for protection or safety: He called security when he spotted the intruder.

  5. protection or precautions taken against escape; custody: The dangerous criminal was placed under maximum security.

  6. an assurance; guarantee.

  7. Law.

    • something given or deposited as surety for the fulfillment of a promise or an obligation, the payment of a debt, etc.

    • one who becomes surety for another.

  8. an evidence of debt or of property, as a bond or a certificate of stock.

  9. Usually securities. stocks and bonds.

  10. Archaic. overconfidence; cockiness.

  1. of, relating to, or serving as security: The company has instituted stricter security measures.

Origin of security

First recorded in 1400–50; late Middle English securytye, securite(e), from Latin sēcūritās; see origin at secure, -ity

Other words for security

Other words from security

  • non·se·cu·ri·ty, noun, plural non·se·cu·ri·ties.
  • o·ver·se·cu·ri·ty, noun
  • self-se·cu·ri·ty, noun
  • sub·se·cu·ri·ty, noun, plural sub·se·cu·ri·ties.

Words Nearby security Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use security in a sentence

British Dictionary definitions for security


/ (sɪˈkjʊərɪtɪ) /

nounplural -ties
  1. the state of being secure

  2. assured freedom from poverty or want: he needs the security of a permanent job

  1. a person or thing that secures, guarantees, etc

  2. precautions taken to ensure against theft, espionage, etc: the security in the government offices was not very good

  3. (often plural)

    • a certificate of creditorship or property carrying the right to receive interest or dividend, such as shares or bonds

    • the financial asset represented by such a certificate

  4. the specific asset that a creditor can claim title to in the event of default on an obligation

  5. something given or pledged to secure the fulfilment of a promise or obligation

  6. a person who undertakes to fulfil another person's obligation

  7. the protection of data to ensure that only authorized personnel have access to computer files

  8. archaic carelessness or overconfidence

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with security


In addition to the idiom beginning with security

  • security blanket

also see:

  • lull into (false sense of security)

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.