firewall
firewall (it) firewall (fx a firewall will provide protection against all hostile software, present or future, a firewall or virus isolator will provide protection against all hostile software, present or future, the company’s security firewall protects all internal information so that only employees can access it, corporate network firewalls, traditional firewalls offer little protection because, to them, SQL injection attacks look like normal web traffic); security firewall (fx most companies have built intranets behind security firewalls, the security firewalls were not up to the job).