Firewall
noun, verb, slang ·Moderate ·High school level
Definitions
- 1 A fireproof barrier used to prevent the spread of fire between or through buildings, structures, electrical substation transformers, or within an aircraft or vehicle.
- 2 (colloquial) the application of maximum thrust wordnet
- 3 The software that monitors traffic in and out of a private network or a personal computer and allows or blocks such traffic depending on its perceived threat.
- 4 a fireproof (or fire-resistant) wall designed to prevent the spread of fire through a building or a vehicle wordnet
- 5 A hypothetical phenomenon where an observer falling into a black hole encounters high-energy quanta at or near the event horizon.
Show 3 more definitions
- 6 (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 wordnet
- 7 An ethical wall; an organizational or legal separation between two entities that might otherwise cause conflicts of interest.
"The book explains this in Adam Hochberg's (@adamhochberg) chapter discussing the Wisconsin Center for Investigative Journalism's concerns related to non-profit news organizations: donor transparency, editorial independence, the firewall between journalism and fundraising, and conflicts of interest."
- 8 An unwritten agreement among major political parties to refuse to govern or cooperate with national conservative and ultranationalist parties. Germany, especially
""Honest government must be preceded by honest negotiations," Mr Kickl said when Austria's president tasked him with beginning coalition talks after the centrist firewall failed."
- 1 To protect with a firewall. transitive
- 2 To block with a firewall. transitive
- 3 To use maximum engine power or acceleration. intransitive, slang
Example
More examples"A firewall will guarantee Internet security."
Etymology
From fire + wall. Compare West Frisian brânmuorre, Dutch brandmuur, German Brandmauer, Feuermauer, Swedish brandvägg, brandmur, Icelandic eldvegg. The verb sense for using maximum power or acceleration comes from the engine's firewall being the limit of forward movement of the throttle controls on many simpler vehicles; thus, to get the maximum engine output, one would push the throttle levers or pedal all the way to the firewall. The politics sense is a calque of German Brandmauer.
Related phrases
More for "firewall"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.