firewall

n. security system for protecting against illegal entry to a local area network which is connected to the Internet (Computers)

A firewall is a hardware or software device which is configured to permit, deny, or proxy data through a computer network which has different levels of trust.
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Noun
1. the application of maximum thrust; "he slammed the throttle to the firewall"
(hypernym) drive, thrust, driving force
(classification) colloquialism
2. (computing) a security system consisting of a combination of hardware and software that limits the exposure of a computer or computer network to attack from crackers; commonly used on local area networks that are connected to the internet
(hypernym) security system
(classification) computer science, computing
3. fireproof (or fire-resistant) wall designed to prevent the spread of fire through a building or a vehicle
(hypernym) wall

n. firewall, security system for protecting against illegal entry to a local area network which is connected to the Internet (Computers)

1. firewall code.
2. firewall machine.