The Oxford Thesaurus An A-Z Dictionary of Synonyms - securityn.

1) safety, shelter, protection, fastness, refuge, safe keeping, sanctuary, asylum: During the air raids, we retired to the security of the basement. 2) confidence, certainty, surety, assurance, conviction: He has the security of knowing that he is right in this instance. 3) guarantee or guaranty, collateral, deposit, gage, pledge, insurance: What are you going to offer as security for the loan? 4 surveillance, safeguarding, guarding, safe keeping, protection, custody, custodianship, care: What plans does the company have for the security of the office building?