() a part of a computer system that is designed to prevent people from getting at information without authority but still allows them to receive information that is sent to them 防火墙（防止窃取信息的计算机系统）◆firewall programs/software 防火墙程序／软件◆The program sits behind a firewall, and cannot be accessed by Internet users directly. 这个程序位於防火墙後面，互联网用户无法直接访问。⨁to build / install a firewall 设立／安装防火墙