(US) The concerted national effort, principally by government, to keep the United States safe and resilient to terrorism and other hazards.

An amount of money paid in advance as security against the payor's non-performance of a contractual obligation.

plural of security community

The protection of information and information systems from unauthorized access and disruption.

(Internet) Security as it pertains to the Internet, such as information security.

A hardware system that prevents unauthorised intrusion into a premises, and reports such attempts. / (computing) A similar software system that prevents unauthorised access.

A facility or part of a facility with minimal restrictions, designed to hold the least dangerous criminals of society.

a prison with more restrictions designed to hold the most dangerous criminals of society; supermax.

plural of security camera

A government organisation established to protect its nation and its secrets from enemies. / Used other than figuratively or idiomatically: see security, service.