noun (n)

• the state of being free from danger or injury(noun.state)

  Example:
  We support the armed services in the name of national security.
  

  Antonym:
  insecurity
  

  source: wordnet30
• defense against financial failure; financial independence(noun.possession)

  Example:
  His pension gave him security in his old age.
  

  Synonym:
  protection
  

  source: wordnet30
• freedom from anxiety or fear(noun.feeling)

  Example:
  The watch dog gave her a feeling of security.
  

  source: wordnet30
• a formal declaration that documents a fact of relevance to finance and investment; the holder has a right to receive interest or dividends(noun.possession)

  Synonym:
  certificate
  

  source: wordnet30
• property that your creditor can claim in case you default on your obligation(noun.possession)

  Example:
  Bankers are reluctant to lend without good security.
  

  Synonym:
  surety
  

  source: wordnet30
• a department responsible for the security of the institution's property and workers(noun.group)

  Example:
  The head of security was a former policeman.
  

  Synonym:
  security department
  

  source: wordnet30
• a guarantee that an obligation will be met(noun.communication)

  source: wordnet30
• an electrical device that sets off an alarm when someone tries to break in(noun.artifact)

  Synonym:
  security measure, security system
  

  source: wordnet30
• measures taken as a precaution against theft or espionage or sabotage etc.(noun.act)

  Example:
  Military security has been stepped up since the recent uprising.
  

  Synonym:
  security measures
  

  source: wordnet30
• The condition or quality of being secure; secureness.(noun)

  source: webster1913